User:JWilgs/sandbox

If Hydra are alarmed or attacked, the tentacles can be retracted to small buds, and the body column itself can be retracted to a small gelatinous sphere. Hydra generally react in the same way regardless of the direction of the stimulus, and this may be possibly due to the simplicity of the nerve nets.

Hydra (/ˈhaɪdrə/ HY-drə) is a genus of small, mostly fresh-water organisms of the phylum Cnidaria and class Hydrozoa.