A betta with shrimps is hit and miss. I've tried 3 bettas with shrimps (one at a time) - one ignored all the shrimps; one ignored the adults but ate the babies; the third killed most of the shrimps before I had time to rescue them. There were bits of shrimp all over the tank.
I always had a nerite snail in with my bettas. Only one ever noticed the snail, and he flared at it when it was on the glass walls. It ignored him so eventually he gave up.
I always had a nerite snail in with my bettas. Only one ever noticed the snail, and he flared at it when it was on the glass walls. It ignored him so eventually he gave up.