Wasp and Hornet Diet and Habits
Wasps and hornets are scavengers no matter where they live. While many wasp and hornet species strictly eat nectar, their larvae need to feed on protein, which typically comes from the source of other insects. Adult wasps and hornets will hunt for insects to feed their young. Their motivation for doing the bidding of the young is driven by a sweet nectar secretion that the larva produces after being fed.
This is why you will find yellow jackets and other wasps swarming sugary drinks, hot dogs and hamburgers. If they can get some of the sweet nectar from your soda can, they can bypass their biological exchange. If they can get a bite of your grilled meat, they have something to exchange back at the nest. You will most likely find yellow jackets around garbage cans in picnic areas or hovering above your spring meal.
Many wasp species live above ground. The paper wasp, for example, uses wood and plants to build nests in trees and building eaves (which hold only about 75 members at the most.) Typically they try and build nests away from people, but if they have a food source and close by building materials for their nests, they can invade places near your home.
Some species build large nests (up to 5,000 members) and they often build them underground or in protected voids. They have also been known to use rotted trees, natural caverns, and some even settle inside wall voids.