Clownfish sitting in corner?

Hi,

So I have had a pair of oscellaris clowns now for a few weeks, and they both seem very healthy. However, the male simply sits in the front corner of the tank, hovering above the sand. But as soon as someone passes and he thinks there could be food he shoots up so he is ok. Is this normal though? He's not being picked on from what I can see and nothing should be scaring him.

Thanks in advance.