Usually OK: watch for signs
Most bugs are harmless to cats, and hunting them is normal behavior. Flies, moths and most household spiders cause no problems. Stinging insects can cause mouth swelling, and a few, such as some caterpillars and venomous spiders, can cause more serious reactions.
What to do right now
- Watch for drooling, swelling or pawing at the mouth.
- If your cat ate a bee or wasp and has swelling of the face or trouble breathing, go to a vet immediately.
- If you suspect a black widow or brown recluse, call your vet.
Why bug can be dangerous for cats
Most insects are simply digested. Risks come from stings (bees, wasps), irritating hairs (some caterpillars), venom (black widow, brown recluse), or insecticide on the bug.
Symptoms to watch for
- Mild vomiting (common, usually harmless)
- Drooling or pawing at the mouth
- Facial swelling (stings)
- Muscle tremors, weakness or pain (venomous spider, rare)
What not to do
- Do not use insecticide sprays or foggers around your cat without checking they are pet-safe.
What the vet will do
Usually no treatment is needed. A vet can treat allergic reactions, stings and, rarely, spider envenomation.
Cat ate bug: FAQ
Is it okay to let my cat eat flies?
Yes, generally. Flies are harmless to eat, though they can occasionally carry parasites. It is natural hunting behavior.
Other "my cat ate…" guides
- String, Thread or YarnEmergency
- PlasticCall your vet
- Rubber Band or Hair TieCall your vet
- IbuprofenEmergency
- TylenolEmergency
- Chicken BoneCall your vet
Sources
This guide is general information, not a diagnosis. Every pet is different: when in doubt, call your vet or an animal poison control line.