Not too long ago, when our party was being attacked by giant centipedes while we delved beneath a fallen fortress I posted a link to a video showing centipedes that hung off cave walls and grappled passing bats. It was pretty horrific and clearly a violation of the established food-chain rules - arthropods should not be eating mammals! Turns out that they're not the only ones. The embedded link is to a Cracked article about bat eating spiders. There's even a video, but I can't see it because Youtube is blocked on my work computer.
There's a whole class of encounter that doesn