Do Cats Eat Flies? Risks & Benefits

After being lost in your thoughts, you realize the cat is also carried away by a fly. Instantaneously, you call out your pet, but it’ll hear none of it. Your feline friend chases down the fly, and it gets you concerned.

Cats are predatory and obligate carnivores in nature, which prompts them to chase down flies and other crawling insects from time to time. They obtain proteins and other nutrients from flies but should keep away from the poisonous ones like scorpions, fire ants, bees, wasps, and some spiders.

As a cat lover, you’ll notice at some point it gets lost in playing games with the flies before killing and eating them. This article explores why cats act as such and to what extent you should allow it to go on.

Do cats hunt and kill flies?

Cats hunt and kill flies even after being domesticated to honor their hunting instincts. Likewise, the larger cat family in the wild survives on hunting and felling small mammals and insects for food. This lives on even when you fully satisfy their hunger.

Hunting and killing the flies is not purely bad for the cats as it helps them keep fit as they run around. Additionally, the flies they manage to hunt down have proteins that boost their diet, which improves their health.

If the cat were to be separated from its caregivers, it would utilize its hunting skills and survive.

Interestingly, as the cat sets out to hunt and kill the flies, you’ll observe it twisting its head left to right. The reason is that the cat is evaluating the distance between it and the prey, so it doesn’t wander off once it sets out to go for the fly.

Most flies your cat will hunt down are small in size, and the chase is thrilling for them as conquering gives it confidence.

Why do cats play with flies before killing them?

Before killing the flies, cats play around with them, and as much as it sounds gross, they enjoy the thrill of it.

Some of the reasons attributed to this behavior include:

1. Train the Kittens

Soon, the female cats expect that the kittens will grow and should be able to cater to their needs. For this reason, they bring a half-live insect or fly for the kittens to play around with before killing it.

It serves as a training ground for the kittens, so they aren’t fearful of hunting down flies in the future once they outgrow their kittenhood.

2. Build on the Skill

Once the kittens have been introduced to hunting by the mother, they need to practice and become better at the skill.

To become an expert in hunting, practice is key. The kittens will play with the partially alive fly with their friend and agemates before the most tactful feeds on it. The exercise helps the kitten hone its hunting skills.

3. Contain Bad Behavior

Hunting and playing with the flies before killing them helps the cat obey its hunting instincts. 

If your cat doesn’t hunt down the flies, it will be bored and less motivated, resulting in bad behavior to use up the energy it could have utilized in hunting.

As they hunt down flies and kill them, they remain active and shed off the extra energy that could have been used in aggression.

4. Caution

The cats want to be sure their prey is harmless. Although the flies are smaller than cats, they don’t like living anything to chance. For instance, some harmful flies and bees can sting the cat, so to ensure they aren’t in danger, the cat will first play around with the flies before killing them.

Is it okay for cats to eat flies?

Too much of anything is poisonous, right? So, although flies are small and seem harmless when the cats hunt them down constantly, they could be exposed to health risks, some of which include:

1. Bacteria and Fungal Infections

Naturally, flies feed on waste which they have to liquidize first. As flies vomit and ingest their feed, they carry bacteria and fungi that could end up hurting the cat.

For the cat to be affected by bacteria from the flies, it has to have consumed a substantial number of flies. However, cumulatively, the flies could transmit these common bacteria to the cats:

  • Salmonella
  • Bacillus
  • Listeria
  • Helicobacter

Once any of these bacteria is accumulated in the cat’s system, it causes digestive issues and could even develop gastrointestinal infections.

Additionally, the flies could transmit fungi to the cats, given their environment, which features different types of fungi. Some of the common fungi that flies could pass on to the cats include:

  • Rhizopus
  • Rhodotorula
  • Moniliella

These fungi will consequently cause fungal infections on the cat, some of which could lead you to the vet if not addressed on time.

2. Infected Flies

Most homeowners quickly spray insecticides on flies and insects when they spot them. Unfortunately, the flies may not die immediately, and if the cats run into them, the chemicals from the insecticides could be transmitted to them.

As a cat owner, secure the pet before spraying it to lower the cat’s chances of feeding on the flies. Although the chances are minimal since flies only need a few traces of insecticides to die, it’s advisable to take precautions.

Cats are affected by the insecticides since they can’t metabolize the toxins found in and on the insecticides.

3. Gastrointestinal Parasites

Some flies harboring parasites could potentially pass them over to the cats, especially when they consume too many of them. Isospora is the most common parasite transmitted from flies and is believed to be behind the coccidiosis infections in cats.

Coccidiosis affects the intestinal tract, which causes the cat abdominal pains, vomiting, and diarrhea.

My cat has eaten flies, is it sick?

If your cat has eaten a single fly just passing by, there is no need to worry. However, if the feline consumes too many, it could make it sick.

After realizing the cat consumed too many flies, check out for these symptoms as they are signs of an  infection as a result of the flies:

  • Vomiting
  • Diarrhea
  • Dehydration
  • Abdominal pains
  • Seizures
  • Writhing and twitching in pain
  • Strained breathing
  • Drooling
  • Isolation whereby the cats prefer to stay alone

If you suspect the cat has had too many flies and starts acting all fuzzy, you need to get in touch with the veterinarian soon to avoid aggravating the conditions, which could worsen the infection. 

Avoid self-treating the cat as you could be endangering it further.

Which insects are harmful to cats?

Some insects and bugs affect the cats causing them infections and prompting you to act fast to save your feline friend.

Some of the harmful insects to cats include:

1. Bees and Wasps

These are stingers, and once they discover the cat coming after them, they act defensively and sting the cat. Luckily the cat will most likely lick off the sting to cool off. 

If the cat suffers an allergic reaction from the sting, consult the vet immediately. They may recommend home treatment such as an antihistamine.

2. Spiders

Poisonous spiders such as the black widow could have devastating effects on the cat. The venom they transmit to the cat has the same results as it has on humans, which should push you to act fast and consult the vet to save the cat.

Only the dangerous spider breeds should worry you. The small spiders you spot in your home are harmless.

3. Scorpions

A scorpion bite is painful to the cat, and if it releases venom, it could lead the cat to develop abdominal pains and vomiting.

Consult the vet on the first aid to administer to the cat to manage the reaction and reduce the pain.

4. Fire Ants

Most ants aren’t poisonous to the cats. However, the fire ants’ bites are painful to cats and could trigger an allergic reaction as they are venomous.

Fire ants can potentially cause anaphylaxis in the cat. It is, therefore, noble to visit the vet before the situation escalates.

5. Wild Hornworms

Wild hornworms, unlike the domestic ones, have a poison called solanine which harms pets that feed on them. They should thus be avoided by your cat.


As seen above, cats kill and eat most insects but should do so in moderation and avoid some poisonous insects. Some may send your cat to the vet while others may kill it – even when the cat has the proverbial nine lives.

Leave a Comment