I have four of these guys. The odd thing about them is that sometimes when they eat they seem to gulp their food and swallow air from the surface. Then they swim at an odd angle, heads down, until they burp a bubble. Then they swim normally again. They all do it at one time or another. At first I thought they were ill, but once they burp they swim normally again. I can't find anything written about this strange behavior. Has anyone else seen their Geophagous do this?