Leeches are such cool creatures. I had a run-in with them while canoeing in Manitoba. Just one or two latched on. It’s really incredible how they can move their bodies around in the water yet maintain the exact texture and fluidity of the water itself. You’d never be able to feel one if it brushed up against you.
Also crazy how well whatever numbing chemical they produce works.
If you want to safely observe one up close, you can get them to latch on to your finger nail where they can’t do any damage.
The paper is behind a paywall, but I suspect the article doesn't say because the paper doesn't come to a conclusion, but I would guess either predation or avoiding being prey themselves.
