Whenever I feed my tank my hermit crabs/thieves climb all over the corals stealing whatever morsels they can get greedy little claws on . The do this to all my corals instantly except the Dendro's. The Dendro's can have food hanging out of there mouths and the crabs walk right by like they cant smell it or know better to try and grab it. The crabs dont even react at all around the dendro's. I wonder if they release something or ?? to keep the crabs away. Anybody experience this with dendro's or other corals?