By Michael Small
So…… if you like to observe squirrels, just happen to notice them or are a squirrel hunter, you may have noticed bumps on their bodies that look like tumors. Gross, right? Well, not to worry. This is a common occurrence in the southeast caused by the larvae of the botfly, a parasite. These bumps and the larvae in them are often referred to as warbles, wolves, heel flies, or grubs. The tree squirrel botfly occurs in about 30 states in the U.S. and unless the individual host is older or suffers from an illness, it will likely recover from the parasite just fine.
So, here’s how it works. Generally, the female botfly lays its eggs on the squirrel which then hatch and burrow under the skin (again, GROSS) where they grow and mature causing the tumor like bumps. Once they are old enough, out they come and fall to the ground. That’s where they mature into adult botflies. Fortunately, these infestations are usually confined from July through September or October. But keep in mind that is just a rule of thumb and they can occur at other times. Also generally speaking, squirrels rarely become infected with no more than five larvae or fewer, and, the larvae are what are known as obligate parasites which means it requires a living host to survive and it is not to its advantage to harm the squirrel. But boy do they itch!
Okay, now that the nasty part is out of the way let’s look into some frequently asked questions about these critters.
1. So should hunters throw away harvested squirrels with warbles because the meat is spoiled?
Answer: Noooooo! The larvae are only right under the skin, not in the muscle tissue. Thus, while the infestation may make the squirrel appear unsightly, these critters are not transmitted to pets or humans. Whew – good news.
2. Do botfly larvae occur in other animals?
Answer: Yup. Other animals such as rabbits, racoons, and chipmunks can also be infested. Isn’t that just lovely? NOT.
3. Can squirrel fly larvae infect humans?
Answer: Afraid so, BUT it is extremely rare AND you cannot get them from an infected squirrel by touch! This is because the larvae under the skin are encapsulated. So, there’s that.
4. Are there ways to prevent these infestations in squirrels?
Answer: Afraid not. These are parasites that occur naturally so there are not any precautions or treatments available. Another misnomer is that these warbles don’t occur after the first frost. Nope, weather does not affect these parasites.
Well, to recap, warbles are pretty much not harmful to humans or any of the host animals they infest. Squirrels infested with warbles can safely be consumed. But, if it makes you feel better, when you’re cleaning your harvest, you can certainly cut around the ugly area before consuming it. And, if it’s just too much for you to stomach (pun intended), then please dispose of the carcass properly and in accordance with your local guidelines. Other than that, try not to be too concerned and, if you’re a hunter, get out there and have a great time.
We sure hope you found these tidbits helpful and cleared up any questions you had!
Disclaimer: The views and opinions expressed on South Carolina Wild are solely those of the authors, and do not reflect official policies, positions, or endorsements of activity or products by the South Carolina Department of Natural Resources.