Catster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Are Lightning Bugs Poisonous to Cats? Vet-Approved Facts & FAQ

Written by: Ed Malaker

Last Updated on May 30, 2024 by Catster Editorial Team

Lightning Bugs

Are Lightning Bugs Poisonous to Cats? Vet-Approved Facts & FAQ


Dr. Alice Athow-Frost Photo


Dr. Alice Athow-Frost

Veterinarian, BVM BVS MRCVS

The information is current and up-to-date in accordance with the latest veterinarian research.

Learn more »

Lightning bugs, or fireflies (family Lampyridae), can be fun to watch and relatively easy to find on a summer evening.  Your cat also might like chasing them around. However, if your cat ate one when you weren’t looking, you might notice them acting strangely, possibly even drooling, causing you to panic. Fortunately, ingesting a single lightning bug isn’t likely to be life threatening for most cats, though they still shouldn’t eat them. Keep reading to learn the potential dangers of these insects and what you should do if your cat eats one.

3 cat divider

My Cat Ate a Lightning Bug! Now What?

If your cat consumes a lightning bug, they might exhibit signs of mild gastrointestinal upset, including drooling, vomiting, or diarrhea. While uncomfortable for the cat, these signs are generally not life threatening, and should pass within 24 hours.  However, seeking immediate veterinary attention is important if you notice more severe signs such as difficulty breathing, change in mobility, seizures, or prolonged lethargy. Luckily, these are only likely to occur if your pet eats several fireflies or is very sensitive to the toxin that some of them contain. If your cat has eaten a lightning bug and you are worried about any of the signs they are showing, always contact your vet for advice.

Lightning Bugs
Image Credit: JumpStory

What Is a Lightning Bug?

Lightning bugs are members of the Lampyridae family, which contains more than 2,000 members. They possess a unique bioluminescence ability that enables them to produce and emit light for multiple purposes, including mating and defense. Males typically use their flashing patterns to attract females, while females flash a unique response, helping to create a mesmerizing display of lights in the night sky.

How Do Lightning Bugs Create Light?

A chemical reaction occurs in special light-emitting organs under a lightning bug’s abdomen.  These photic organs, or ‘lanterns’, create the light that we see as these bugs fly around. The light creation involves the enzyme luciferase, the substrate luciferin, oxygen, and other cofactors. Other insects, including the glowworm and click-beetle also use this same process to create light.

Lightning Bugs
Image Credit: JumpStory

Toxic Compounds in Lightning Bugs

Certain lightning bug species possess a defensive steroid called lucibufagins, which has a bitter taste and in some cases, can be toxic to predators. These lucibufagins are present in the bodies of lightning bugs and discourage predators from eating them. However, the quantity of lucibufagins found in one lightning bug is usually insufficient to cause significant harm to larger animals like cats unless they eat several in quick succession.

cat + line divider

Risks of a Cat Catching a Lightning Bug

Fortunately, the risk of your cat catching a lightning bug is low as these small insects often fly out of the range of your pet. Also, many cats that do catch one will quickly spit it out due to the taste of the lucibufagins, and will be unlikely to try again. That said, cats are also fast and can jump quite high, so it’s better to call them inside if you notice these bugs catching your pet’s attention.

cat lying on blanket looking sad or sick
Image Credit: Julia Cherk, Shutterstock

cat face divider 2

Keeping Your Cat Away From Lightning Bugs

1. Supervision

The most effective way to ensure your cat’s safety around lightning bugs is through supervision. If you spend time outdoors with your cat during the evenings, when lightning bugs are active, watch their interactions, and intervene if your cat becomes too interested in chasing or consuming these insects.

2. Closed-Off Porch

Another way to prevent your cat from eating lightning bugs is to close off your porch or deck with a screen or netting to create a bug-free zone that your cat can play in. Closing off the porch can also be effective in keeping other nuisance insects out.

Image Credit: B-E, Shutterstock

3. Indoor Playtime

If you’re concerned about your cat’s exposure to lightning bugs, consider creating a safe indoor play environment. Engage your cat with interactive toys and puzzles to help take their mind off going outside, where they might encounter lightning bugs.

cat + line divider

Frequently Asked Questions

Can Cats Recover From Eating a Lightning Bug?

Fortunately, the toxins in a lightning bug usually only lead to mild gastrointestinal distress in cats, like vomiting and diarrhea, which should pass within a few hours. Due to the insects’ bad taste, it’s unlikely that your cat will eat more than one, but you should still call them into the house and watch them carefully, notifying the vet if any adverse signs don’t pass over the course of 24 hours.

Do All Lightning Bug Species Contain Defensive Compounds?

No, not all lightning bug species contain defensive compounds like lucibufagins, but with so many different species, it can be hard to determine which bugs do and which bugs don’t. Certain female lightning bugs, namely those in the genus Photuris don’t contain the defensive toxins but will lure a male of a different species to her by mimicking another species’ flash pattern, and will eat the male to gain his toxins. She will then inject these toxins into her eggs to protect them.

Image Credit: castleguard, Pixabay

Can I Still Enjoy Lightning Bug Displays With My Cat Around?

Yes, you can enjoy lightning bug displays with your cat, but be sure to supervise their interactions. Keep your cat on a harness and leash or within a safe distance while the bugs are most active to prevent your cat from chasing or eating them.

Are Lightning Bugs Beneficial in Any Way?

Yes, lightning bugs play a beneficial role in various ecosystems. They are natural predators of other insects, snails and slugs, and contribute to controlling pest populations. Additionally, their beautiful bioluminescent displays serve a purpose in mating and communication within their species as well as being amazing for us to watch.

Are There Any Long-Term Effects If My Cat Frequently Eats Lightning Bugs?

There are no known long-term effects if your cat occasionally consumes lightning bugs. However, it’s best to prevent frequent ingestion to avoid potential gastrointestinal discomfort. If you notice any unusual or persistent signs, consult your veterinarian immediately.

3 cat divider


If your cat just ate a lightning bug, they will likely try to spit it out immediately. If they do swallow it, they may suffer mild discomfort, including vomiting, diarrhea, and drooling. Fortunately, it shouldn’t be life threatening, and the discomfort should pass within a day, hopefully leaving your cat hesitant to  try another. Still, it’s a good idea to call your vet and let them know what happened so they can advise you on the proper course of action.

While it’s difficult for cats to catch lightning bugs, it’s not impossible, so it’s better to call them into the house when these bugs are most active, especially if you notice your pet chasing after them.

Featured Image Credit:

Get Catster in your inbox!

Stay informed! Get tips and exclusive deals.
Catster Editors Choice Badge
Shopping Cart


© Pangolia Pte. Ltd. All rights reserved.