Fighting? Chirping crab?

[CrabDad]

Daughter is 10 and is New to the crab ownership and having some major Drama from the three crabs we have. - ironic but I have three daughters that create drama as well!

Three crabs - Large Carl, two smaller Mufasa and Tiger Late last night I found Tiger out of his shell (second time) and Mufasa trying to "hump" the empty shell. He wasn't trying to get in it and wasn't being aggressive to the shell-less crab but he was all over the empty shell and looked like he was humping it as weird as that sounds. I removed the shell-less Tiger and placed him in a small container with some new shells... he picked a really big one that he can get WAY up into... This is where it gets really crazy - I fell asleep on the couch and woke up about 5 am and heard a LOUD chirping sound and the big guy Carl, was all over Mufasa and had an arm in his shell. I didn't know if it was mating or a fight but I separated them. I had no idea crabs could chirp like that. The really weird part is that Carl and Tiger (the largest crab and the smallest most reclusive crab) seems to get along pretty well and spend almost all day side by side in the "hut". It seemed like Carl was attacking Mufasa because Mufasa was on Tigers shell earlier... Like he was sticking up for his buddy! HA! That's not possible is it?? He didn't even see it as he was in the hut when it happened. Was Carl's arm in Mufasa's shell because he was trying to get him out? Also what does the chirping mean??
Thoughts?
Thx,
Crabdad

[curlysister]

A few questions. How big is your tank? How much sub is there? What are you feeding? And how many extra shells do you have for them?

[CrabDad]

tank is a 30 gallon, about 4.5 inches of sub and it's sand and EE mix. feeding them veggies, fruit, and a protein (crickets, peanut butter, chicken etc) and about 7 or 8 shells in there - I have read what other have on this and I guess I need more shells but they never seem interested...
THX!

[curlysister]

I asked about the number of shells, because I wonder if the one crab was possibly interested in the other's shell? HCA does recommend 3-5 extra shells per crab, so that would be 9-15 extras. Maybe they haven't seemed interested in the shells because there wasn't a good selection? There are also proper and improper shells - check out the shells guide for info.
Your crabs also need a source of calcium daily. Egg shells, cuttle bone, coral are some good sources.
How big are your crabs? Your sub could probably be a bit deeper - HCA recommends at least 6 inches, or three times as deep as your largest crab, whichever is deeper.
How are the temp and humidity? What do you use for water?

[CrabDad]

I added egg shells about three weeks ago and I see them on or in the egg shells pretty regularly. The biggest crab and shell are about the size of a golf ball. They used to dig and bury every night when in a ten gallon tank but once I have moved them to the 30 gal. they don't seem to dig as much. I have added a new hidey hut and a moss pit. The biggest and smallest stay in the hut all day and the medium and most active (Mufasa) beds down in the moss pit every day. temp is a bit low right at 77-78 during the day and 80-82 at night but not really off - the humidity is up around 85%. they have HUGE water areas both salt and fresh but I have NEVER seen them drink or get into the water and it is clean - no sub in there. They are quite active at night with Mufasa coming out first, tiger second and the big guy Carl coming out last and staying up the latest. they crawl and climb a net I have in there that crosses the whole tank, they climb a coconut fiber mat that goes across the back of the tank and they climb the cholla wood... I think I need to get smaller water areas to give them more room to walk around...? I want to add a second level of stuff but I would have to take them out and stress them out during the meantime to do it...