how to remove crab

[diavids]

can anyone tell me the easiest/best way to remove hitchhiker crabs from a 20 gal tank. I think i have two crabs, one is a larger brown one who i have seen shrifting through the sand and rocks finding food. The other is a smaller while crab (stone crab?) someone has been nibbling on my zoa's so i'm pretty sure its the crabs, so they need out. I can't really remove the rocks, so what has worked for pls here. My firefish has become very defensive regarding his lair as the one crab seems to like the same spot. So now he's staying close to home. any help would be apprecaited.

[Wheelman76]

Once the lights are out get a glass and tip it at an angle and lean up against a rock so the crab can climb in ,and place it close to where the crab likes to hang out. Put a piece of shrimp or other meaty food in the glass , when he climbs in to get the shrimp he won't be able to climb back out of the slippery glass.

[JmeJReefer]

Bait n wait. Try at night too. It's a "whenever u can see it" kinda situation....
Good luck