June 17, 2026, 11:21 am | Read time: 5 minutes
Grasshoppers, beetles, or spiders trigger the hunting instinct in many cats. However, some insects can cause injuries, allergic reactions, or even life-threatening conditions. PETBOOK highlights which creepy crawlies require caution.
1. Spiders
Since there are only a few venomous spiders in Germany, the risk of a cat experiencing health issues from eating one is relatively low. Spiders can bite if they feel threatened, but there are only a few species that can penetrate the thicker skin on a cat’s paws or legs.
A bite from the common cross or water spider in Germany is similar to a bee sting, while a bite from the introduced thorn finger or Nosferatu spider is like a wasp sting.
If a cat is bitten by a spider, it can cause circulatory problems and swelling at the bite site. However, the amount of venom is usually so small that there is no significant danger to the animal.
2. Larger Beetles
These insects are not toxic to cats. However, there is a risk that a cat could choke while sniffing or playing with them. A beetle could get stuck in the throat and cause breathing difficulties.
An allergic reaction is also possible, as some creatures are allergic to May or June beetles. In such cases, the cat’s throat may swell, causing it to wheeze due to lack of air. It may also refuse to eat.
If a cat vomits, it may have eaten a May, June, dung beetle, or earwig. The wings, shell, or exoskeleton are partly made of chitin, which is indigestible for cats and can cause vomiting after consuming such an insect. This vomiting is usually harmless, but parts of the insect could remain lodged in the throat. It is advisable to monitor the animal and respond quickly if further symptoms appear.
3. Grasshoppers
Grasshoppers are not toxic, but when playing with one, it can happen that the grasshopper’s barbed legs get stuck in the cat’s mouth or throat. This can cause significant pain and pose an acute choking hazard. This also applies to locusts and crickets.
If you notice your cat showing symptoms of breathing difficulties after eating one of these insects, a veterinarian should be consulted.1
Also of interest: Poisoning in pets – what you should do now
4. Oak Processionary Moth
The caterpillars of this moth are dangerous to both humans and animals. They are primarily active in forests from March to May. Afterward, these caterpillars develop into harmless moths that no longer pose a threat.
The oak processionary caterpillars have stinging hairs containing the toxin thaumetopoein. These hairs can be “fired” in defense when they feel threatened or can be released upon the slightest contact. They stick to the opponent with their barbs. Contact with the toxin is similar to touching nettles but much stronger, leading to severe allergic and inflammatory reactions, especially on mucous membranes. Therefore, this insect is very toxic to cats.
Symptoms of contact between a cat and the oak processionary moth:
- Skin irritations, itching, burning, blistering
- Breathing difficulties
- Eye irritation
- Dizziness, vertigo
- Fatigue and fever
- Swelling of the tongue, throat, and neck
- Life-threatening allergic shock
If there is any suspicion or contact with the oak processionary moth, a veterinarian should always be consulted as a precaution to rule out or immediately treat a severe allergic reaction.
5. Black Oil Beetle and Stink Bugs (Shield Bugs)
Both beetles secrete a substance when they feel threatened. The oil beetle’s secretion contains cantharidin, an irritant and neurotoxin that is toxic to all living beings. The result is skin irritation, rash, inflammatory reactions, or blisters.
Ingesting or coming into contact with a stink bug leads to increased salivation in cats. This poses no health risk and usually doesn’t last long. However, some animals are hypersensitive to the stink bug’s secretion, which can cause gastrointestinal issues or vomiting.2
6. Black and Red Ants
Common and widespread black ants are fun to watch and play with. Cats often eat them as a snack. They are not toxic, so consuming these insects is harmless for cats.
Red ants, on the other hand, attack and defend themselves when threatened. They bite, which can cause unpleasant pain, itching, swelling, and allergic reactions.3
These Insects Can Be Life-Threatening for Cats
Dog Stung by Bee or Wasp–What to Do Now
7. Bees, Wasps, and Hornets
It goes without saying that no living creature, whether cat or dog, should ever chase a bee, wasp, or hornet. The sting of a bee, wasp, or hornet is even more dangerous for cats due to their size and the concentration of venom than it is for humans. Additionally, a sting is usually extremely painful. The sting site and surrounding tissue swell, the skin becomes red and painful, itchy, or hot, which can severely restrict and impair the cat. Licking and biting the affected area can lead to a serious infection.
The greatest danger is if the cat is stung in the mouth, throat, or neck, as this poses an acute life-threatening situation. The tissue may swell so much that the cat can no longer breathe and may suffocate.
Watch for These Symptoms
Symptoms after an insect bite, sting, or possible poisoning:
- Swelling or closing of the throat, mouth, and neck
- Breathing difficulties, wheezing, or gagging
- Increased salivation4
- Vomiting
- Diarrhea
- Refusal to eat
- Disorientation and coordination difficulties
- Circulatory problems
- Unusual behavior
My Tip as a Health Advisor for Cats and Dogs
If a cat is an avid outdoor explorer, curious and playful, it won’t shy away from insects because it is unaware of the danger. It is advisable to observe the animal after it comes inside. If it shows signs of an insect bite, sting, or poisoning from eating a toxic insect, a veterinarian should be consulted as a precaution.