Diurnal Fireflies

While painting blazes this past weekend, I kept running into these beetles and sometimes even had to flick them away. They're very common on tree trunks this time of year. I'm sure you've seen them at some point. Today I grew curious about the beetles and looked them up.

They happen to belong to a genus of fireflies that don't light, also called "diurnal fireflies" because they are active during the day. They breed on the tree trunks in March, which is why certain tree trunks have a lot of them.

Here's the underside of the firefly. The abdomen is all black, unlike most fireflies, which have a light-colored lower abdomen where they light up.

If this sort of thing interests you, here is a really nice description of these fireflies and how they live.