Emerald crab gone rogue

[rpc07]

I have had this emerald over a month and it has never as much looked at my corals. Tonight I fed the tank like I normally do and about 15 minutes later I spot fed my 2 acan frags. Well not 5 minutes after that I see the emerald crab picking at the acan at first I thought he was trying to get at the food but then I saw him ripping parts off the acan. I quickly shooed him off the frag and away and he ran into the Rock work. 10 minutes after that I see him on my green star polyp frag ripping at those.

Is it normal for them to snap all of a sudden and start going nuts on corals?

Another question I have is I just added a strawberry crab and was also told those are reef safe. Should I be worried?

 

[MidwesternTexan]

Bring him to my reef!

I've only a bowerbanki, but he can have all the gsp he can find!!!!

 

[csb123]

Someone once said "never trust a crab."

 

[SLOreefer805]

Yeah crabs can be hit or miss. My first emerald crab was doing awesome eating algae around the tank. One day I caught him picking at my zoas. I was like..."maybe it's just a one time thing". So I ignored it. A few days later he was eating another. That's when he found a one way ticket back to the petstore. They really didn't want him either since he was now labeled as a coral killer.

 

[Bogue Chitto]

I found what looks like a stone crab as big as a mason jar lid in my tank yesterday. I didn't know it was in there. It grew from a tiny one hidden in some live rock I bought and thought was clean. Now I have to try to devise a trap for it.