Yellow jackets will become the most active during the late summer and fall. I’ve received a few calls
from people saying that they have encountered some around their homes. I have a few around my own
house, so I know they’re out there! Yellow Jackets can look similar to wasps. Wasps are usually
unaggressive unless threatened. Yellow jackets have a thicker waist, shorter legs, and wings that press
more flatly against the body when resting than wasps.

Wasps’ nests are usually under eaves or beneath porch railings and have hexagonal cells. Yellow jacket
nests are usually built in old rodent holes or cavities that have been left behind by a small critter. They
can build nests in wall spaces, although this is less common. Yellow jacket nests will die out over the
winter and start anew with a new reproducing female each year. This means that yellow jacket nests will
be the easiest to eradicate in the spring while the nests are still small. The flipside is that the nests will
be harder to find in the spring because they only have a few individuals in them at that time. Nests can
grow up to 5000 yellow jackets, and will grow larger in years with a long dry spring.

Solitary yellow jackets can often be seen foraging for food for the colony. Yellow jackets feed on a
variety of insects pests. They will also eat meat and like drinking coke. They will also attack bee hives.
Yellow jackets are able to discern at a pheromone level which hives are weak. They’ll choose those hives
to attack, making them more of opportunistic pests to bees than actual predators. If they are able to get
inside past the guards, yellow jackets can take out the entire hive killing bees, eating larvae, eggs,
pupae, and honey.

Control of yellow jacket nests this time of year can be very difficult because the nests have reached a
large size. Pyrethroid insecticides that you can buy at the store will be effective at killing yellow jackets,
but only when you make contact with them when you are actively spraying. If you can block the hole
that they use as an entrance you may be able to eradicate them this way too. Yellow jackets aren’t
diggers, they use holes other critters have made, so they can be trapped inside if there is only one
entrance. There are yellow jacket traps that can be effective at controlling them too. Another method of
control is to use hot water mixed with dishwashing soap and pouring it down the hole. Whenever you
are working with yellow jackets the safest time will be at night. They will be more inactive at nighttime,
so your chances of being stung decrease. It is still a good idea to wear protective clothing. If you have a
serious yellow jacket problem it is best to call a professional to control them.

If you have any questions about yellow jacket identification or control please call your local Extension
Office or email me at [email protected].