Histeridae

I didn't want to put it in the beetle section because I didn't want to give away the ant stuff.

But clown beetles are a really fun group of beetles that are also parasites of larvae of various different species.

But there's a 99 million year old clown beetle that was described in 2019 that And it is the oldest known example of a behavior based on symbiotic relationships.

So again, these are beetles that exist today that are really unique looking.

They have very tanky bodies and will emit pheromones to pacify their ant hosts.

Many look like scarabs, but there's also the flat clown beetles that are literally a millimeter thick.

So like the thickness of a credit card.

And they burrow underneath bark to eat larvae that are in the bark.