Nasty crabs!!! HELP!!
 

I recently received some used, live rock which has housed 2 crabs. They hide all day (obviously), and just happened to see a white one moving from the "cave" in the new live rock.
Google says to use Krill tied to a small rock placed in the bottom of a cup. Going to give that a try, I just started my tank 1 month ago, so don't want to lose the fish I have.
Any other ideas would be greatly appreciated.
Thanks!

How big of tank ? What did the crabs look like claws ? Are the crabs hairy? I had a few nuisance crabs and worms in our old tank, chances are if ther are two they maybe more or other pests. I caught the ones I had at night using a light and trapping them out of there hiding spots. U can try the cup and krill might work too if u can keep all ur fish snails and crabs out.

Don't get me wrong I hate ALL crabs.. But not likely there is any realistic chance of a hitch hiker crab taking down a fish. I haven't tried it but take the rock out ( knowing the crab is in it) take it to the sink and with a turkey baster full of tonic water squirt it in his hiding spot any try to flush him out. Then you can get the hammer out for a little fun. Try not to soak the rock too much with the Tonic water.

I have a 65 gallon tank. I'm truly hoping there are only 2 crabs in there... Lol
From what I could see, it was pure white, no fuzzy claws. The second one is a dark color, didn't get a good look at that one before he took off.

The hammer is ready... Hahaha
Just need to trap him first!! :)

Are you kidding?!?!?

It's best to omit that advice about crabs not taking out fish. It's horribly wrong!

I had a 20g reef with two crabs in the past. A hairy crab and a purple red eye crab.

I lost a couple small gobies before I went after them.

Try jam a screw driver into the hole they are in. Sometimes you can kill them. I got one that way, the other was harder and I ended up selling the rock to someone who never cared it was there.

Ya I will get right on that.

Have patience T its not an emergency your fish and those crabs have been together for years. Set the trap and wait.... Patience is the key in this hobby for everything!

Yeah was saying sometimes your lucky with the crabs not be intrusive. Usually I have found if they have a hairy body and legs there nasty. If there claws look pointed they is a chance there bad, and the few I Lund had lack tipped claws. I have found usually the bad crabs seem to have really creepy eyes like red or some weird colour. I would say a health fish should be able to avoid the crab less they catch them sleeping, I would lean more to the crab going after other crustacean or corals. But as Jason was saying be patient look into the tank once the lights go out and see if u can find where they hide then its usually a matter of time before you can catch them with tweezers.

Thanks everyone, they just freaked me out a little. No capture yet.. Can't even see them at night now. They're spotted once, must have went to find a new hiding place. Lol
Patience is something I need to have a little more of when it comes to the nasty critters. :)
I'll keep you posted!!