Do they need water to breathe? Can they use the aqueous properties of blood to breathe? If you get out of the water and don’t go back, do they eventually just fall off and die? What’s the long term play for them there?
JimZ
They absorb oxygen through their skin. As long as they stay wet, they are fine.
The First Dragon
A leech will let go and fall off when it has finished feeding.
It is an annelid like an earthworm, so it needs to keep damp; and they need to get back in the water sooner or later.
Leeches do not carry disease, but they do put anticoagulant into the wound, so it can take a long time to stop bleeding, and leave a bruise. Not actually dangerous, just annoying.
daniel g
They are a parasite and attach to suck a little blood/plasma. They get their fill they usually detach and fall off.
Sticky buggers to pull off.
They can survive out of water until they desiccate, technically dehydrating to death.
They need water to breed and survive there. More the brine marsh sort.
Anonymous
I don't think I'll have to be
Chloe
Pretty sure you die or lose more blood if a leech stays attached?