it depends on the size of the anenome. I have seen them get a grab at green chromides. They nibble them right up. The sting is not bad. you will feel a little tingle.
I had a carpet anenome ONCE, it had a diameter of about 7". I picked it up by the foot to move it. it slipped and turned insideout over my hand. I was down in the E.R. for 6hours with a saline IV and a blast of cortizone to kill the sting and itching. BBBBAAAADDDD JUJU.
