What might these growths be? and removing harmful crabs.

[Youngster Dan]

Originally Posted by newreefer_59

Also, on the bird's nest, I have 2 resident crabs that came for who knows where. I think the symbiosis is cool, but am told they have to go. Is there a trick to trapping them? or is a pair of tweezers the only way to go?

What do the crabs look like?