Opossums: The Unsung Heroes Against Lyme Disease And Other Tick-Borne Diseases

Several states in the U.S. are reporting record populations of ticks and increasing tick-borne disease transmission, like Lyme disease, but clearing your yard of these blood suckers might be only one opossum away. Yes, that giant rat-looking animal that plays dead when threatened and hisses like the devil’s spawn when scared is actually extremely beneficial to humans and other mammals. Opossums’ diets include snakes, snails, slugs, mice, rats, and carrion. Perhaps the most intriguing item on an opossum’s daily menu is an even more dreaded human foe: the tick. Opossums’ voracious appetite for ticks can nearly obliterate a tick population.

Scientist Rick Ostfeld points out that few ticks survive a run in with an opossum. These animals, often called filthy, are actually remarkable groomers and spend almost all of their free time grooming themselves. Ticks are attracted to these mammals, but most of them never survive on an opossum’s body long enough to taste a single drop of blood.

“So these opossums are walking around the forest floor, hoovering up ticks right and left,” Ostfeld explained, “killing over 90% of these things, and so they are really protecting our health.”

Michigan State University entomologist Howard Russell told the Detroit Free Press that the tick population is increasing. Russell says that both male and female ticks feed on blood and these thirsty bloodsuckers can transmit diseases like Lyme and Rocky Mountain spotted fever.

Lyme disease is in Texas. The Texas Lyme Disease Association notes that there are seven reportable tick-borne illne… pic.twitter.com/5F22ezw7of

— Angela LeBrun (@Angela4design) May 26, 2015

Robert Pinger, professor emeritus of physiology and health science at Ball State University, told the Indy Star that in the past couple of decades, the population of deer ticks, which is a host for Lyme disease, has grown exponentially in the U.S.. According to Slate, reports of tick-borne diseases have doubled since 2003 and tripled since 1995 in America.

We just pulled the biggest tick of Lilly! Poor thing! pic.twitter.com/IGnTkNQLic — iBallisticSquid (@iBallisticSquid) May 22, 2015

Possum Posse bragged about the opossum’s powers of fighting our tick foes after reading a study in the Proceedings of the Royal Society B.

“The new paper’s authors, Keesey et al., caught a range of tick hosts — white-footed mice, eastern chipmunks, gray squirrels, opossums, veeries, and catbirds — and experimentally infested them with ticks. They found a huge range of tick success across the six host species: almost half of all ticks introduced onto mice were able to feed, while only 3.5% of ticks introduced onto opossums were…Wild-caught opossums carried an average of almost 200 ticks — if that’s 3.5% of the ticks that try to feed on a opossum, then that means each opossum had attracted, and eaten, up to 5,500 ticks!”

That’s in just one week. An opossum successfully grooms off and kills and average of 5,686 larval ticks every week. The DFW Wildlife Coalition also sang praises to the opossum.

“When left alone, the opossum does not attack pets or other wildlife; he does not chew your telephone or electric wires, spread disease, dig up your flower bulbs or turn over your trash cans. On the contrary, the opossum does a great service in insect, venomous snake, and rodent control. He takes as his pay only what he eats, and maybe a dry place to sleep. The ‘possum tolerates our pets, our cars, prodding sticks, rocks and brooms. ‘Attacks’ by opossums are simply non-existent. When he gets too close, or accidentally moves into your attic space, he can be easily convinced to move along. If you are lucky enough to have one of these guys come around, you can rest assured he is cleaning up what he can, and will soon move along to help someone else.”

Many people use the rabies excuse for ridding their properties of opossums, but that justification is a false one. According to Wildlife Rescue and Rehabilitation, opossums are “rarely found to be rabid and appear to be resistant to many viral diseases such as distemper, parvovirus, and feline hepatitis” and this resistance to diseases is also seen with Lyme. The Poughkeepsie Journal reports that opossums don’t seem to be very good transmitters of Lyme disease even if they didn’t eat almost all of the ticks they encounter.

Ticks do transmit Lyme disease, and Lyme affects around 300,000 Americans a year. An opossum, normally viewed as nothing more than a filthy nuisance – stealing garbage, garden surplus and chicken eggs – kills over 5000 ticks on any given week. This super exterminator also kills venomous snakes and small rodents and cleans up carrion from our yards and fields. Perhaps allowing opossums to also steal some chicken eggs and garden veggies is a fair trade for decreasing tick-borne diseases like Lyme and all of the other benefits they offer.

[Photo via Possum Posse]