University of Maryland Extension: Garden Q&A
A: Because many of them are using the same hole, they are probably yellow jackets, a wasp that forms colonies in voids, often in the ground. Yellow jackets are voracious predators of plant-feeding insects such as caterpillars and beetles which they feed their young, so they are a big help to homeowners.
On the other hand, they may sting if you disturb their nest. Adults feed primarily on sources rich in sugars and carbohydrates, such as fruits, flower nectar, and the occasional soda. With heavy freezes, they all die except the queen, who leaves and overwinters elsewhere.
Yellow jackets are so beneficial that we recommend ignoring a nest when it’s located where it will not be disturbed, but your nest is too close. Go ahead and spray the hole at dusk with an aerosol hornet and wasp spray.
Q: I’d like to take advantage of fall plant sales. Do deer eat Japanese maples?
A: That depends on each individual deer’s taste, how hungry it is, and how young, tender and convenient the tree is. Japanese maple is not usually a favorite. Deer are browsers, however, and may nibble plants until they grow out of reach. If you have a lot of deer pressure, you may want to select a taller variety of Japanese maple. Fence it when young.