Is it safe to remove a wasps’ nest without killing the wasps? If not, how can wasps be killed to remove the nest?
Our guess is you’re not willing to wait until the first hard frost, which will kill them off, but it’s almost impossible to get rid of wasps safely and humanely.
You can knock the nest down with a stick or by blasting it with a hose. (Do this on a cold night, when the wasps are less aggressive.) But even if you remove it, the wasps will return and try to rebuild in the same spot. Hanging an insecticide strip inside will drive the wasps away, but could also kill them.
The most efficient way to get ride of the nest is to destroy it and kill everything inside. (Sorry, wasps.) An ordinary spray canister of wasp-killer will work, though if the nest is small—less than the size of a grapefruit—and up against a solid surface, you can squash it with a 4×4. Try this with a larger, mature nest, however, and you’ll get stung.
Before you do anything make sure that the nest doesn’t belong to the giant European hornet (look for its reddish-brown head), a non-native with a very nasty sting that has been spotted in Ontario in recent years. In this case, call in a pro.