I have seen wasps flying in and out of a hole (a few inches wide) near a tree, and I had presumed a wasp nest in the ground. Within one week of spotting the sight, a very large hole was in this spot (probably 10 to 12 inches in diameter) with dirt clearly displaced. Could this possibly be the wasps? Or is another large ground animal, such as a ground hog, also involved? I'm wondering whether I should go ahead a spray with a wasp killer, now that it's colder outside or if I should contact an exterminator. Thanks J.

Sounds like a ground digging animal was trying to get into that nest. Do you still see any activity during the warmest part of the day?

If the holes don't go anywhere it could have been dug by a skunk or raccoon, which both eat insects. Skunks commonly dig holes in lawns looking for insect grubs and worms for food. Ten to twelve inches, though, is larger than I expect. Raccoons are also notorious for digging in lawns. Their damage is often messier, and they will often roll the turf out of the way to get to the dirt underneath. Groundhogs, are primarily herbivorous, but apparently will eat insects, but I am unaware if they exhibit the behavior you describe.http://icwdm.org/inspection/groundholes.asp

Many wasps are annual nest builders. When winter sets in, the wasps will mate and hibernate, to start a new nest somewhere else, next year. Although, nests may occasionally be re-used. Honeybees, though, build perennial nests. If conditions are mild the nest will survive through the winter and become larger with each year.

Some ground nesting wasps and bees are beneficial and not aggressive. Control is not necessary. However, if they are the ornery type, earlier in the year, it might have been useful if you wanted to DIY to use a specific wasp insecticide. These insecticides will shoot a stream, so that you can stand back from the entrance, and have a knockdown ingredient such as pyrethrin, to make stinging incidents less likely. You might also want to spray when it is cold so the wasps, such as early morning, so the wasps are more sluggish. Or hire it out, to avoid the risk entirely.