Wasps living around your property are more than an annoyance; because they work so hard to defend their nests, they can become aggressive and sting people or pets. If you understand wasps, you may be able to kill them relatively easily yourself, but you should pay close attention to safety procedures when you kill wasps.
If you are allergic to wasp stings, you should not attempt to kill them (Reference 1). Even if you are not allergic, the risk of being stung while killing wasps is fairly high, so Bugspray.com suggests wearing protective clothing similar to a bee suit (Reference 3). If you do not wear a bee suit, you should at least wear heavy coveralls with boots, heavy gloves and a veiled hat (Reference 1). Because wasps are able to get inside clothing, you should secure your pant legs, sleeves, collar and any other opening in your clothing with masking tape (Reference 1).
Locating the Nest
If you see wasps flying into and out of a single location, they probably have a nest there (Reference 1). In order to effectively kill wasps on your property, you will need to access the nest. Carefully follow the wasps, and locate the nest opening during the day, when fewer wasps are around (Reference 1). According to Pest Control Canada, it is best to kill the wasps at night because most of the wasps tend to be in the nest at night. Also, wasps can't see as well at night as they can in the daytime, so your risk of being stung is lower (Reference 2).
Kill the wasps with an insecticide made for wasps (reference 1). As with any insecticide, follow the directions and precautions on the label. Take a flashlight with you when you go to the nest in case you need some light to find it (Reference 1). According to Bugspray.com, if you have a handheld bug zapper, you may want to bring it so you can kill any wasp that flees the nest (Reference 3). Approach the nest slowly, spray the insecticide over the nest and any escaping wasps according to the package labels, and the insects should die (Reference 1).