I was at the pet store, getting cat food and as I always I went to see the rodent section. There was a faily who was planning on getting a small pet and they were looking at the rats. I didn't notice it then, but once they left, I saw that there was THREE adult rats in an about a 1 foot by 1/2 foot by 1/2 foot glass cage with only small vents for air! The poor rats were crowded around the vents trying to get air. I heard one sneeze, too.