Is this normal

[ryn_C_mu]

So I have had a citrus goby for 2 weeks coming this Saturday and after a few days he seems only at night and every now and then during the day will go and glue himself to the glass tonight though he would swim at the very top and then he goes back down for a while and then goes back up close to the top so is it normal

 

[Bectan01]

I think so, do you have something he can perch on? I have some branching Duncan's which my goby loves to sit in. Might help?