I don't know what it is. However, what some do say on here is that they believe if a tort can eat it they will. If they aren't suppose to eat it, they won't. I have pulled some of mine, some I haven't, and he hasn't touched it. You can always go with the when in doubt, pull it. See if someone knows what it is.
He doesnt seem to pay much attention to it, but im going to pull it out anyways. Im kinda curious to find out what it is. I'll keep searching google. Haha