[Doane]

I recently purchased 2 stapps and placed them in my 20g. Everything seems fine until the evening when one of them goes to sleep in shell A and the other seems to wander the tank without sleeping. But the next day the fish that slept in shell A is guarding shell B and the poor guy who got evicted is guarding shell A. I have a total of 4 shells in the tank, but they always seem to be around these two.

What should I do so that both are happy?

 

[Darkside]

Add some more shells so they have more choices. That'll likely cheer them up.