cat obsessed with fish tank
Questions About Cats

How to Keep a Cat Out of a Fish Tank

Cats and fish tanks can be a challenging combination. By introducing them to your house, you are mixing predator and prey. You must take steps to prevent your cat from accessing the fish in an aquarium.

Keep your cat away from the fish tank by making it inaccessible. House your fish somewhere with no launch pads to climb. For security, fasten the lid of the fish tank. Deter the cat by applying sticky tape and unappealing scents to the aquarium’s roof.

If kept separate, cats and fish can co-exist in the same home. In fact, aquariums can be an endless source of visual entertainment for felines.

Do Cats Like Fish Tanks?

Many owners of cats and fish complain that their feline is obsessed with their aquarium. This may appear strange, as most cats detest water. However, there are many reasons why a cat is besotted with a fish thank.

Colors and Movement

Feline vision is designed to respond to stimulation. This includes bright colors and sudden movements. The more exotic the fish in your home, the more fascination an aquarium will provoke.

Multiple fish, in particular, will continually pique a cat’s curiosity. Swimming fish move in small, jerky motions. This will be spotted from the corner of a cat’s eye. The cat will then investigate, discovering the numerous occupants of the aquarium.

how to keep cat away from fish bowl


Depending upon the fish you keep, your tank may be heated. If so, the heat will rise. This will make the lid of a fish tank cozy to a feline. Your cat may lie on the fish tank, enjoying the warmth that this provides.

While this will be a welcome respite from the winter chill, it must be avoided. Your cat may fall into the tank or frighten the fish. There is also a risk that the cat burns its skin through prolonged exposure.

Ensure that your cat has an alternative, appropriate heat source during colder months. Blankets and hot water bottles will perform the same role as the heat from an aquarium lid.


Never underestimate feline hunting instincts. A predatory cat may eat fish from the tank. This is likelier in some cat breeds than others.

As explained by bioRxiv, cats are patient when hunting fish. Felines are happy to lie in wait and pick off shallow swimming prey. This makes pet fish easy prey for a hungry cat.

Raw fish is one of many toxic foods to felines. If your cat eats raw fish, its body will be unable to create thiamine. A lack of this B-vitamin can cause neurological issues in cats.

Running Water

If your cat keeps drinking from a fish tank, it hears the constant flow of fresh water. The cat is interested in drinking from there because it creates the ‘illusion’ of freshness. Cats dislike drinking still water from a bowl.

The cat will frighten fish by constantly drinking from the aquarium. The cat may also swallow stagnant water or fish feces and become sick.

Muffle the sound of this running water and provide your cat with an alternative, such as a water fountain.

Unclaimed Territory

Both cats and fish are territorial animals, but occupy different spaces. The underwater domain of a fish is of no interest to a cat. The tank, on the other hand, is available to claim.

Some cats will claim a fish tank as a place to nap and relax, even if the cat has no designs on harming the fish. The cat will cause issues by spending time around a fish tank and needs to recline elsewhere.

How to Protect Fish from Cats

If you are keeping these two species as pets, you must cat-proof your fish tank. Primarily, this is to protect your fish. The more the cat stalks the tank, the more stress the fish feel. The cat may also escalate to hunting.

You also need to protect your cat from itself. If your cat falls in a fish tank, it could be in peril. Drowning is unlikely, but the cat will get soaked. This can lead to hypothermia, if the cat does not escape and dry off quickly.

Some fish have defense mechanisms to deter predators. Betta fish and cats should never interact, for example. This antagonistic fish contains toxins that could harm a kitten or senior cat.

There is also the risk of a cat eating raw fish. This not just a sad end for a fish. The cat can make itself unwell doing so, or even choke on small bones.

Relocate the Tank

Given half a chance, a cat will climb on top of a fish tank. The more difficult you make this task, the less inclined a cat will be to do so.

If possible, keep your tank close to the ceiling. You’ll need access yourself, without the use of a stepladder. A gap that is too small for a cat will keep it out. Cats enjoy snug spaces, but there are limits.

Also, limit your cat’s ability to climb onto the fish tank. This means reducing the number of launching pads. Do not locate any furniture near the aquarium. Cats will use sofas or armchairs to climb. A standing jump will only take a cat so far.

If you have a lightweight tank or bowl rather than an aquarium, a cat will be able to knock over these vessels without any problem. It will proceed to eat the fish, leaving broken glass in its wake.

Seal The Tank

Cats are crafty and sharp-witted. If your cat is determined to access a fish tank, it will find a way. You’ll need to protect the fish.

Most reputable tanks will be fitted with a lid. These will contain small holes for air and feeding. In most cases, these are too small for a cat’s paws. However, small gaps can be made larger with determined clawing.

Once the lid is in place, ensure that it is secure. If you do have air holes and feeding slots, you can tape down the lid. Use strong, electrical standard tape. Make it impossible for a cat to cut the tape with its claws.

You may also want to consider weighing down the lid. Be careful as cats knock items over for a range of reasons. Whether by accident or design, this can be dangerous for your cat, fish, and family.

Add netting below the lid, inside the fish tank. If your cat does open the lid, it cannot swipe and snatch the fish inside. This will not resolve the anxiety provoked by a cat’s presence, though.

Unappealing Textures

The easiest way to keep a cat away is double-sided sticky tape. Cats dislike sticky sensations. It clings to the paw pads and feels uncomfortable.

Cats dislike aluminum foil. Many cats enjoy crinkling sounds, but the shiny, cool material is not to feline tastes. Most cats will avoid direct interaction with aluminum foil.

Unappealing Scents and Noises

Cats are often guided by their senses of scent and hearing. Playing sounds that the cat does not like, or applying scents, can keep cats away.

As per Hearing and Sound Communication in Fishes, fish have poor hearing. Noise is less likely to upset aquatic pets. Consider an ultrasonic device on low volume so you have are bothered by the sound.

Apply citrus, mint, mustard, or rosemary to the top of the tank. Cats will give these aromas a wide berth. Be aware that fish have a strong sense of smell, which can be a further source of stress.

cat obsessed with fish tank

Cover the Tank

If you are unavailable to supervise your cat and ensure aquarium safety, cover it up. This technique is most effective at night, while you are sleeping. If the cat cannot see the fish tank, it is less likely to show interest. Just put a breathable towel or blanket over the tank.

This technique is best used sparingly, though. As explained by the Journal of Veterinary Behavior, many veterinary surgeries house fish tanks because they entertain and amuse cats.

Cats notice when their humans are not home. Aquariums can work in tandem with windows to stave off separation anxiety. As long as the tank is secure, your cat can contentedly watch it for hours.

Distraction Techniques

If your cast insists on circumnavigating your deterrents, you’ll need to distract it. Simple but effective techniques for this include:

  • Loud noises, such as handclaps or whistles
  • Unpleasant sensations, such as a shot of water from a squirt gun
  • Vocal commands, like a stern, “no”
  • Offering playtime with a favored toy

Kittens are easier to train than adult cats. A senior cat, in particular, may grow indignant about this training. If a cat sees an aquarium as its territory, it can be tough to prevent interaction.

When your cat stops interacting with the fish tank, provide a treat. This could be food, catnip, or attention – whatever your cat values most. Make it worth the cat’s while to cease interacting with the fish tank.

Never release the treat while the cat is still engaged with the aquarium. Teach your cat that leaving fish alone earns rewards. If the cat associates treats with the fish tank, it will be determined to gain access.

There is no reason why you cannot have an aquarium and a cat in the same home. You’ll need to keep your cat out of the fish tank.