I have two pleco's, both of which are very large and very old. The owner i bought them off of claims that they are 10 years old, and i believe him. One is about 13 inches long and the other is 10 inches long. However, the 13 inch acts sort of strange. He acts just like any other pleco most of the time, but whenever i feed my cichlid's with my floating pellets, he eats some too. He'll be just chilling, sucking on the glass, and when a pellet floats above him on the surface, he'll inch up and put half his mouth above the surface of the water, and suck in the pellet along with air. Do they always do this? I'm worried that him sucking in air isn't a good thing, and that he shouldn't be eating that kind of food.