Unfortunately the video did not work for me. I’ll have to use my imagination on this one.
If there is some sexy music playing in the background, perhaps some wine, I would venture to guess they are doin it! Specially if you see them rubbing their ugly bits in and out. As if one is trying to jam it’s telson into the females Gonopores. (Yes, that is what their naughty bits are called).
Buuuut if it looks like one is being ejected out of its shell to increase vacancy due to lack of shell space or number of shells....you might have a brawl on your hands. Do you have enough and different size shells?
Yup. They can't grow shells so the try to rip out other inhabitants to steal the shell. Sometimes it's just bullying it seems. When mine did it he would roll them around and try to dig into one but never pull the other out.