hornets and yellowjackets are good for gardens. this is because their prey is mostly made of insects which are considered pests. they also feed on bees, but their colonies only last for a year, they die in winter. a medium-sized colony, made of 300-400 animals will need about 500g (half a kilo, 1 lb) of food per day, during the high season, that is in the summer months. animals hunted include flies, wasps, bees, locusts, beetles, caterpillars, dragonflies and spiders.