AI walking on body-like mesh

[Ysseret]

The body is static. Right now I hope just to make AI climb and walk randomly on mesh, but if climbing is to much of a trouble, might try to spawn AI on the body.

[Bohrium]

What do you need the AI to actually do? Does it have to climb up the body, or run around in a circle on the body, or have some more complex behaviour like two spiders having a deathmatch on top of his dome? Also will the body be in motion or static?

[Ysseret]

Is it possible to create an AI for any kind of insect (like spider, roach, fly etc.) to walk on mesh like human body? Obviously, navmesh won't help here. Having some "move to target point" doesn't work for me either. Any suggestions?
I included screenshots of body what I got.