Aquarium hobbyists that own other pets, such as cats or dogs, can run into issues when these other pets become curious about your aquarium. Cats, being agile creatures fascinated by movement, love staring at aquariums. I can’t say that I blame them. However, when the cat becomes too curious, they may climb onto the top of the tank and try to get whatever is inside. The cat may fall into aquarium if it doesn’t have a cover, and it may deposit hair or chemicals found on the hair (think tick and flea medication) if its tail or paws get into the water.