What you are seeing is an adaptation that corys have to enable them to get additional oxygen when their native rivers become muddy. They are actually taking gulps of air and swallowing them. The oxygen is absorbed into their system in their intestines.
This is just fine as long as it doesn't continuously happen. It's like humans yawn if they are in a stuffy room to get a bit more oxygen. If it persists, you might want to give your water parameters a check and see if the surface of the water is moving so that it refreshes the oxygen in the water.
thanks inchworm, i was searching through my dad's things in the garage and found an old air pump, i rigged this up with some plastic tubing and purchased an 6" air stone, the cory (Jason) is now doing this much less frequently, thanks again for the info