Found throughout North America, yellow jackets or various species of wasps are familiar to picnics yet do not generally attack humans or animals without provocation.
The supermodels of the flying insect world, adult wasps, 1/2" to 3/4" long, have narrow waists, long, cylindrical legs, smooth, shiny skin and two pairs of fairy-like wings.
After feeding on sugary treats such as flower nectar and the juice of ripe fruit, adult wasps prey on flies, caterpillars and crickets which they feed to their developing young secreted in a papery nest made from chewed wood mixed with saliva. These nests are built in a myriad of locations from underground to tree limbs, building eaves and wall voids. Nests located out of areas of human disturbance will normally be fine left alone. The wasp colony will die after one season except for the queen who overwinters, emerging in the spring to locate a new nesting site as she will not reuse an old nest.
Wasps sting to defend themselves and their colonies, injecting venom before they withdraw their stinger without harming themselves so they are capable of stinging multiple times. The sting location may be treated with ice, vinegar, meat tenderizer, topical ointments and even antihistamines if the victim's immune system is compromised. This information is not intended to supplant medical advice and those with known allergies to insect stings are always advised to carry adrenaline-based injectors on their person when outdoors during the warm seasons.
If wasps have built a nest too close for human comfort, a non-toxic method of nest control involves enclosing the nest AT NIGHT (when wasps are least active) in heavy plastic before severing it from its attachment point and dropping it into the "bag" and sealing it. Freezing the bag/nest will kill the wasp colony as well as sitting it in open sun for a couple of days.
So, wasps can be as beneficial as well as pesky pests so if they are just hanging around and not bothering anyone, let them be. They can help pollinate and rid the yard and garden of other pests.