boreworm spawning only in water ?

[Furandooru]

seen 6 boreworm so far across dif level and area in my mine but all spawned in the water being unable to move and looking awkward... guessing its not meant to spawn there.

[Hrenli]

Have similar experience. Saw a boreworm "in" water. Quotation marks because I decided to fight him (had to take a boat to reach him) and it turned out he was not in water but sort of stuck on a coast line and didn't chase me. That didn't make the fight any easier for him, obviously. I thought I got just lucky with that one particular boreworm, but you say they all seem to be like that?