A green Brittle or Black ? Greens are known to be rather aggressive, and very active. The blacks are more passive, but not as active and tend to stay in one place alot. To feed them just spot feed them a piece of shrimp or krill with your hand. Once they get use to it they come right out for dinner.
Mine, I cup my hand with the food and he comes out wraps two or three tenacles aound my fingers till he finds the food then snags it and back into the rocks he goes. But when he comes out for my hand. it reminds me of some B rated horror flick