Nano Mantis tank-algae over growth?

[MantisFreak]

How do Mantis shrimp hitchhike in? I guess the Rock I got was a bit different, cause I couldnt see anyplace where a critter could hide while I was pulling off the dead sponges and whatnot.
Zero

My hitchhiker mantis in my reef tank most likely came with a coral I bought a couple of months ago. That's the only purchase lately. You would be shocked at how small of a hole they can live in.