Sometimes fish will brush up against different objects in the aquarium in an attempt to remove ich and other irritating external parasites from their skin. Though this behavior does mean something unwanted is present, there’s no need to knee-jerk react to the fish’s behavior, unless of course the fish is covered in parasites or is in poor health. More often than not, a simple water change and increased feedings can cause a fish’s maladies to disappear, but if they persist, more drastic measures might need to be taken. Heavily infested fish need to be removed from the aquarium as soon as possible and placed into a hospital tank. The treatment can then commence, and the fish can receive extra special one-on-one care that it couldn’t receive in a well-stocked aquarium.