Top Photo: One of three known bald-faced hornet’s nests at museum this year.

There have been at least three active bald-faced hornet nests on our 84 acre campus this year. It’s likely there were more, but only three were discovered. Two of the hives were found by the sharp eye of Ranger Martha who is always on the lookout for mycelium.

As is often the case when searching for one thing, you’re often surprised by the serendipitous discovery of something at least as interesting as your initial objective.

A bald-faced hornet begins the season by awakening in spring from winter hibernation. She’s one of a group of female hornets hatched at the end of the previous fall.

Soon after emerging from hibernation, she starts a small hive and lays a batch of eggs within. The eggs hatch into worker hornets (all females) which take over the hive’s building and maintainance while the original female, the queen, settles in to laying eggs to produce even more workers.

Besides helping to further enlarge and reinforce the hive, which may grow to be two feet high and over a foot wide, the workers feed and care for the nest’s ever growing population of larvae and pupae. The workers are also charged with protecting the hive. The hive may contain or support more or less 200 – 400 individuals.

In the fall the queen will lay a final group of eggs which hatch into both fertile females (potential queens) and males. It’s now that the females leave the hive, mate, and seek out a secure location to hibernate for the winter, starting the process all over again.

All the workers, the old queen, and the males die off during late fall or winter, depending on your latitude, leaving the hive empty. The hive will not be used again by the hornets.

If you find a hive and you’d like to collect and perhaps exhibit it, I would wait at least until the first hard freeze to make sure there are no lingerers in the hive.

We’ve had a few nights where the temperature momentarily dipped into the high 20s and low 30s, but it was apparently not cold enough to freeze out all of the hornets, at least three emerged from the hive (above photo) when we were removing it from the tree. The hornets were chilled enough to be flightless, never-the-less it may be wise to wait to harvest a hive until temps drop to the high 20s for an extended period in order to be sure there are no living hornets in the hive. Definitely avoid bringing it inside until that time.