Cichlid behaviour

I have isolated one of my severum cichlid in an seperation box with a hole in the box for filtration. But the other mate severum again and again enters that box I don't know how or why. And start nipping it .I tried placing the box in such a way that the other severum do not enter it . Kindly reply to it . Please !!!

OB Guy

Staff member
I'm not sure what your "separation box" looks like but the only way to keep other fish out of it would be place the hole close enough to the glass or other obstruction to prevent the other fish from entering. Welcome to the forum.