Odd behavior - rubbling legs, getting chased

[Hollym2247]

I have 4 hermit crabs. 2 have been here almost 3 years. They are golf ball sized (Dora) and a little bigger (alien). I have 2 new crabs I just brought home about 4 weeks ago. They are much bigger, but smaller than a tennis ball.

Alien has been dug under and probably molting for about 6 weeks. He is in the original tank. I set up a second to protect him.

I introduced the big guys to Dora slowly, and they've been fine for a month.

Today, she has been rubbing her feeder claw with her pincer and front legs, kind of marching in place in the sand. After a while, the two big ones started chasing her around the cage. I moved her to my smaller ISO tank. She ran around like crazy for an hour, but finally settled down. The two big guys settled down in their usual spot as soon as I took Dora out of the tank.

Is she getting ready to molt too? Did a big crab maybe injure her feeder claw? Should I keep her separate and for how long? Thanks.

[soilentgringa]

This sounds like typical crab behavior to me. They rub their legs and bodies with their grooming appendage to clean themselves.
They may be establishing a pecking order as well.
Did you check the new crabs for mites before introducing them into the tank?
It's not necessary to separate the crabs unless you see active signs of aggression, such as pinching the other crabs legs or forcibly trying to pull them out of their shells.

[Hollym2247]

Yes, checked for mites.

Dora has never acted like this in the 3 years I've had her.

The bug crabs did get aggressive with her once before when she was scrambling all over them. One was reaching into his shell with his pincer. The other knocked her across the cage with his claw.

The other odd thing was all this rambunctiousness was happening in the middle of the day.

[Hollym2247]

Today big brown and big stripes chased Dora across the cage and big stripes knocked her out of her shell.

Why we'd this start after they were already together a month? Dora has been unusually active. But she was on the other side of the tank, and they were both sleeping by the heater before it all started.

[JulesRolyCrab]

Does she have her shell on?? Or is she naked? Naked crabs should always be considered an emergency and I would post as such if so.
I would separate them for now until more can be done. Are there lots of shell in the tat? How big is the tank? Only three crabs? Species? Etc. post any necessary details here or (if she is now naked) in emergency, the first thing you'd want to do is get her back into any shell.

[Hollym2247]

She got right back into her shell and has been climbing all over the that, eating, drinking and splashing in the water.

Currently 3 PPs in one 10 gallon and 1 PP (her prior tank mate, he's been down for weeks) molting in the other 10 gallon. Plenty of shells or all sizes, and the bigger crabs could never fit in Dora's shell. He didn't do the tapping of before a shell fight. This suggestions time I have watched him in broad daylight get up, chase her and whack her with his big claw.

Neither crab's behavior appears normal to me. I think Dora is hyperactive and the bigger guys are annoyed.

[Hollym2247]

That's suppose to say "that's the second time" not suggestion.

[JulesRolyCrab]

That is very odd. What do you feed them?
The only major concern I see is size. I would immediately upgrade tank size or else put one of the larger ones in the other tank. 3 is too many for a 10 gallon unless they are teeny tiny, and even 2 crabs in a 10 gallon is cutting it if they're large. 2 smalls is a-okay though. How large would you say the crabbies are?

[Hollym2247]

I'm moving to a 30 gallon as soon as I can integrate them all. I can put drawback in the original with the molting crab.

The two small ones are ping-pong and golf ball sized (I've had them 3 years). The two big ones are bigger than a golf ball, but about half the size of a tennis ball.

I feed them commercial crab food pellets, diced apples, mineral supplement, crushed oysters, dried blood worms, and a commercial flaky protein mix from the hermit crab patch. Fresh food and water every night.

Dora has been eating like crazy, the big ones must eat at night because they're pooping plenty!

[Hollym2247]

I'm afraid the larger crab might dig up my molter.

[soilentgringa]

Oh yeah, the pellets usually have toxic preservatives in them. A tennis ball sized crab is what I'd consider jumbo sized, at the very least a large bordering on jumbo. It needs 15 gallons alone plus the tank should be about 18" wide so that it has plenty of space.
Petco is having their dollar per gallon sale right now and honestly if you can afford it, I would suggest a minimum of 40 gallons. I know it seems large but your medium crabs can become larges in one molt.

[Hollym2247]

There are no preservatives listed in the food. Again, I've been using it 3 years, and my original crabs have been fine. It is in addition to fresh foods and various powdered/flaked food and supplements from HCP.

The big crabs are about HALF the size of a tennis ball.

Are you suggesting their diet may contribute to this odd behavior? Although it has not been changed? Thanks for any info.

For now, they are in separate tanks.

[Hollym2247]

A baseball, my largest crab and my smallest crab. And yes, she has plenty of natural shells to choose from, but has chosen to go back to the painted one she inherited from her tank mate when he outgrew it.

[Hollym2247]

Well, now they're both dug down in separate tanks. Ill buy a 40 breeder, but can't establish it until they all come up!