September 07, 2008

yellow jackets: a farmer's experience

Every year about this time I get really leery about wandering around our farm.

In late summer, as fall approaches, the yellow jackets (Vespula spp, YJs)

increase their activity, and seem to get angrier and meaner. Most years I try to

stay indoors as much as possible to avoid getting in their way. They make

outdoor suppers quite an adventure, as we try to eat while shooing the unwanted

guests away and hoping they don't turn on us with their stingers.

Before we moved to our previous farm and started raising chickens, I had never

really thought much about yellow jackets vs. wasps or other bee-like creatures.

However in the summer of 2001, we had our first encounter with a YJ nest.

Friends were visiting and they had gone with Rich for a walk in our forest when

they unwittingly walked over a nest. I heard them yelling and laughing as they
ran for the house... if I remember right, they all were stung at least once.

That was the first nest we found at that farm, but not the last. We quickly

learned to watch our step in the pasture while tending to our pastured poultry

flocks, so as not to step into a nest - the only evidence of presence was usually

an angry “guard” or two, and a very neatly manicured hole.

dispatching the YJs – the early days

We also learned that boiling water was helpful for destroying nests. However, it

was a precarious endeavor as it involved hauling pots of boiling water out into

the pasture under cover of night, shining a light toward the nest only long

enough to spot the hole - but not long enough so that the buzzing masses would

fly out and attack - and then pouring the water into the hole and backing off to

a safe distance. There's little that gets your adrenaline going quite as quickly

as hearing the rising buzz of a thousand YJs with a flashlight trained on their


The whole water procedure usually had to be repeated 2-3 times, and then Rich

would take a shovel (still at night – never, NEVER attempt this during the day)

to dig at the nest and make sure it had been destroyed. Amazingly, Rich only got

stung once or twice during the night time raids, and usually by a YJ that would

have survived the initial water attack and crawled up the shovel handle while he

was dismantling the nest.

We thought we had battling the YJs down to a science until we moved to our

present farm, where we soon realized that the size of the property and number of

nests meant that our old tactics were not going to work.

Now, we generally don't use chemical fertilizers or pesticides of any kind on our

farm, the only exception being the very occasional use of Round-up to assist tree

establishment or control noxious weeds. We tried the “organic” boiling water

method of YJ slaughter at first, but realized that hauling boiling water in our

truck out to the far side of the main pasture was not very efficient, especially

since each nest took many gallons of water for successful destruction

So we tried getting creative. We used soapy water instead of plain water hoping

that would reduce the water necessary, but nope. We tried venting the exhaust

from our truck into a nest, but with no success. We talked with people who

recommended pouring gasoline into nests, but we just couldn't stand the thought

of the long-lasting effects on our soil from that solution. We even contemplated

the YJ's natural role as decomposer, and wondered how many YJs we could live with

on the farm (not that many!).

In the end, we started using YJ spray to kill the nests, making sure not to run

the livestock over those spots.

a hunting we will go...

Before you kill a nest, you have to find it. And I have to say, I've gotten very

good at finding YJ nests over the past few years. Rich now knows to send me out

hunting for the nests, and I'll usually find at least 1, and sometimes even 2 or

3. I actually really kind of enjoy looking for nests. Apart from the buzzing,

and those darn adrenaline surges from when you think you've just stepped on a

nest, it's actually quite peaceful. Okay, maybe peaceful doesn't quite describe


If you lived here...

YJ nest openings are a fascinating glimpse into the hive mind. Nests on our farm

are usually located in dry, warm areas – rarely if ever in the bottom of a swale

– often on a south facing slope. They seem to prefer areas where the grass is

somewhat short, but that doesn't always determine nesting siting. A nest opening

looks very different from a mouse or other rodent hole because it's very

symmetrical in shape (often a perfect circle), and usually has only dirt around

the circle extending about another inch or two out. It's extremely neat. And if

it happens to be surround by grass, the grass has been cut back around the hole

as well. One nest I found a couple of weeks back was absolutely beautiful in its

symmetry and neatness – a 4-5 inch circle of vegetation was cut away, surrounding

about a 2 inch wide circle of bare dirt, carefully packed, surrounding the one

inch nest hole. It was like the YJs had read a book about what their nest should

look like, then set out to make it as perfect as possible.


Some nests seem to have 2 openings. I'm not sure if those nests are so large that

they decide that a circular driveway is better than a regular one. Or if in

some cases, the YJs create a second opening if we had attacked the first side.

I'm just saying, watch your back!

Something I find really interesting is that YJs generally will nest in the same

area year after year. Perhaps there's something particularly enticing about a

specific spot, or maybe there is some kind of genetic memory of “home” that gets

passed down to the next generation.

hunting conditions

You can go looking for nests anytime, but my favorite time is either early in the

morning, or in the late afternoon. It's easier to see the movement of the YJs

leaving or approaching the nest when the light is slightly lower, or if there are

long shadows. It needs to be warm enough that they are still flying though – I

went out nest hunting too late recently, and the YJs had all gone to bed.

It also helps if it's quiet out. Normally our little piece of heaven is pretty

quiet, but those days when the log truckers are zipping by with the jake brakes

on, or the neighbors are using the chainsaw -- those days are not meant for YJ


To every YJ, there is a season...

Time of year is also important. Yellow jacket activity starts during the spring

each year when the hibernating queens wake up and find themselves a home. During

the winter, if you find any large yellow jackets, perhaps tucked into a jar of

nails (like the one that stung Rich), or between bales of hay, your best bet is

to kill them. If you don't kill all the overwintering queens (which is a tough

goal since they are generally hard to find), it's a good idea to put out traps

with bait during the first warm days of spring.

Our goal is always to kill as many queens as possible in spring, because fewer

queens mean fewer nests. Those queens that don't take the bait (and we've found

that store bought traps and attractant work better than anything we've rigged up

with soda bottles, etc.) start churning out little YJs whose main role is to

bring back food and to build the nest. We see these guys hanging around our

Noble firs in spring, collecting sap. At this point, it's still too early to

find most nests.

We generally start nest hunting (or accidently stumble across a nest) sometime

around mid-July. The YJs have produced many brethren by then, and they are

starting to get ornery. We continue the hunt until late August or so. By that

time, we've usually found all the ones closest to the house, and are willing to

live with the ones in our back pasture, or across the road.

walk softly, carry big stick (or flagging)

Hunting YJs involves patience and a lot of quiet watching. I'll usually start

along a path and will walk very slowly, stopping every 5 feet or so. (Don't

assume that there are no nests on your farm paths... we've found many a nest on

well-travelled paths, although usually not until mid summer, by which time we've

probably walked right over the hole many times.) When I stop, I survey the path

ahead to look for YJs. The key to finding a nest is to look for vertical

movement. Foraging YJs are usually moving horizontally across the ground. YJs

going in or out of a ground nest are usually moving vertically.

There's also a 3rd type of movement which I call “travelling”... this is when you

see YJs making a beeline (ahem) across a wide swath of land. These YJs are most

likely travelling from a nest that is farther away, directly to a source of food

or water. Seeing this type of behavior clues me in to the fact that some of our

YJs are probably visitors, perhaps nesting just across the road from our place,

or maybe on the very front corner of our property that I don't tend to visit.


With companions like these...

I prefer to go YJ hunting solo, or with my cats. Okay, have you stopped

laughing? Our 2 farm cats actually like to go on walks, and unless they are

being really annoying and laying down right in my path (which they enjoy doing),

it is actually rather helpful if they walk a little ahead. They are stealthy

enough that they can troll for YJs (who look for movement) and you can look for

YJ movement. In fact, I actually think walking like a cat on the prowl is sort

of the right mode for YJ hunting... take a few cautious slow steps, look around,

then continue.

Although my dogs often tag along as well, they are not so helpful, and I often

worry that they will rile up a nest right before I walk over it. Plus one of

them likes to run off, so I end up spending more time worry about the dog than

looking for nests.

One thing I don't recommend is walking behind an ATV or any other kind of vehicle

on our farm during YJ season. I made the mistake of doing that a few years back,

and ended up being stung multiple times after walking across a nest that had just

been zoomed over by the neighbor's ATV. You should have heard this farm gal

yell. In fact, the boys next door almost got quite a show as I tore off my shirt

(luckily I was wearing layers) to try to get the YJs off me. I think I lost a

lot of my tough farm woman cred that day. But I digress...

Wear your rubbers!

Okay, so maybe rubber boots aren't necessary, but clothing that covers you up is

probably a good idea, especially if you are new to YJ hunting. At the very

least, I would not recommend sandals or flip flops – boots and long pants at

least provide some protection. And while I've never been stung while hunting for

a nest (okay, now I'm doomed) it can be dangerous, especially if you

inadvertently anger nest residents. I've read stories—well, I won't go into

them, but keep in mind that a yellow jacket nest could have thousands of

residents... They may be small, but they definitely have you outnumbered.

beware the watcher

If I'm buzzed by a YJ while I'm standing still, I'll usually move back a few feet

(to ground that I've already deemed safe) until the buzzing stops. If I'm buzzed

while moving, I'll either move forward (watching the ground) or back. Then I'll

cautiously reapproach the spot where the buzzing happened. Sometimes it will

just have been a rogue feeder, checking you out, and maybe engaging you in a game

of chicken (I usually give in first). But sometimes it can be a “guard” YJ,

stationed near a nest entrance, who has the job of harassing anyone who gets too



If I get buzzed repeatedly, I'll watch the area from a safe distance, and look

for the tell-tale vertical movement. Once I see it, I'll slowly move a little

closer to see if I see YJs flying up and down from the same spot. Sometimes I've

been fooled by YJs who are approaching the same spot, but only to drink water

(such as dew off the strawberry plants) or eat something (yummy, dead rodent!)

Sometimes it helps to approach the potential nest from a different angle, as the

hole may be oriented one way or another. Watch for the vertical movement, and

imagine a helicopter landing and taking off... that's what the YJs look like.

Coming in to the nest they slow a bit as they approach, and leaving, they pick up

speed as they move away from the nest.

The delicate part is here... you have to get close enough to ascertain whether

there is actually a nest hole, but not so close that you anger the residents.

I've been able to positively identify a nest from about 3-5 feet away. I'll

stand nearby and watch the YJs behavior until I'm positive that I've found a

nest. Then I'll usually lean in or move a bit closer until I actually can see the

hole, then move back so as not to anger anyone (and also to let that adrenaline

rush end.)

(By the way, even looking at a picture of a YJ is enough to raise the hairs on

the back of my neck and make a shiver go through me... it's sort of like what my

high school English teacher described as a “fascination with abomination”... the

YJs creep me out, but somehow I love to hunt them.)

After you're certain you found what you're looking for, it helps to get close

enough one more time mark the nest for the person who will be dispatching it.

Or to alert others working on your farm to stay away from that spot. Anything

bright can work... lately I've taken short pieces of hay twine and added some

masking tape to one end to make a flag. Plastic flagging tape works well also.

It helps if it won't blow away, but try to avoid throwing anything very hard

directly at the hole, for obvious (I hope) reasons.

a good year

Some years we've found and destroyed as many as 30 nests during the summer.

According to Wikipedia,

nests can produce 4000-5000 YJs during a season – that's well over 100,000 YJs

potentially on our farm some summers! Even a conservative estimate of 20 nests

producing 2000 YJs means potentially 40,000 of the critters buzzing around. (And

Rich wonders why I don't like going outside in August).

Luckily, we've been dealing with YJs long enough that we may have broken the code

this year. So far (it's now early September) we've only found about 6 nests, and

the population seems very low compared to previous years, based on the limited

activity we've seen around the house and on the fields. It probably helped that

it was a late, wet spring – the queens probably got a slow start. Plus we think

we caught a large number of queens in traps in the spring. And I think a huge

factor is that we stopped raising chickens for production (eggs and meat) a

couple of years back. The spilled chicken food was probably a huge source of

feed for the YJs. We like that they are not really fond of hay or grass...

Whatever the reason, this is the first summer in many years that I've been able

to enjoy being outside in September. I may still decide to eat my hamburger

inside the house this weekend, but at least I can wander around without the

constant buzz of ornery yellow jackets to keep me on edge.

[An aside by Rich....using Val's conservative estimates of 40,000 members of the

hive mind populating the farm, and making another conservative assumption that

each one will eat 2g of protein (carrion, bugs, chicken food) per day, that means

that in the big yj years, 80 kg/175lb of protein passes through them every day.

Truly, the piranhas of the Northwestern September.]

Posted by rich at September 7, 2008 11:03 PM