They give you rad protection and light
If you get a leech/lamprey just stand on a fire or get a tribemate to stab it off, if this will not work simply check your tames for leeches
When they attach themselves you are immune to radiation
They protect you from the stupid nameless
And the radiation
Put in basket on abbreaviation to tame it or kill it for leech blood for fishing for BPs
Put a fish basket and wait for a leech to get in it but u can also tame. Coelacanths and mega perrannna!
And if you have no armor on when they try and kill you they cannot they can almost one shot you
Find a small pond in the biulimnecent area then place a fish basket. There are so many you would probably get one.
It is amazing you can actually ride this thing out and drinks blood but you have to get it