Aquarists often use glass tops or mesh screens on their tanks to keep their fish from jumping out and drying out on the floor into crispy little strips of fish jerky. But if you’ve got other pets, namely cats, then those protective coverings might serve as more of a barrier to keep things out. Cats and other pets are insanely curious about our glass boxes and all of the potential little snacks swimming around in them. They can jump on top of tanks, knocking stuff into the water, scaring the fish, or even falling into the water themselves. While this activity normally occurs at the top of the aquarium, don’t doubt that it could also happen in your sump if the doors do not latch.