These insects can be solitary or live in group nests above and below ground. Yellowjackets can be aggressive when defending their nests so avoid the area where possible. Paper wasps on the other hand will avoid contact. When eating outdoors, keep foods well covered. One strategy is to put out bait such as a piece of meat or an opened soda can some distance from the table before setting out the human food. Trapping the queens in the spring and workers during the summer can reduce local populations. See the UC Pest Note on Yellowjackets and Other Social Wasps for more information.