Opossums Kill Ticks, Help Stop the Spread of Lyme Disease-Mostly Truth!

Opossums Kill Ticks, Help Stop the Spread of Lyme Disease-Mostly Truth! 

Summary of eRumor:
Opossums stop the spread of Lyme disease because they kill up to 4,000 ticks a week.
The Truth:
Claims about possums and ticks are mostly true — but the amount of ticks one possum kills in a week has been skewed.
An “Awesome Possum” meme, as it has become known, was posted at the image-sharing community website FunnyJunk.com in mid-March. Within days, it had been shared thousands of times on Facebook, and the legend of the Awesome Possum was born:
The idea is that even though possums are scary looking scavengers that prowl in the night for animal carcasses to feed on, they actually serve an important purpose: preventing the spread of Lyme disease by “hoovering up and killing” up to 4,000 ticks a week, each.
As it turns out, there’s scientific evidence to support the “Awesome Possum” claim. It comes from Richard Ostfeld of the Cary Institute for Ecosystem Studies in Millbrook, N.Y. The Cary Institute reports:

And now ecologists have learned something else about opossums. They’re a sort of magnet when it comes to riding the world of black-legged ticks, which spread Lyme disease.

“Don’t hit opossums if they’ve playing dead in the road,” said Richard Ostfeld, of the Cary Institute for Ecosystem Studies in Millbrook, N.Y.

Ostfeld is forest ecologist and an expert on the environmental elements of infectious diseases like Lyme disease.

Several years ago, scientists decided to learn about the part different mammals play in the spread of the ticks and the disease.

They tested six species — white-footed mice, chipmunks, squirrels, opossums and veerys and catbirds — by capturing and caging them, and then exposing each test subject to 100 ticks.

What they found, is that of the six, the opossums were remarkably good at getting rid of the ticks — much more so that any of the others.

“I had no suspicion they’d be such efficient tick-killing animals,” Ostfeld said.

Indeed, among other opossum traits, there is this: They groom themselves fastidiously, like cats. If they find a tick, they lick it off and swallow it. (The research team on the project went through droppings to find this out. All praise to those who study possum poop.)

Extrapolating from their findings, Ostfeld said, the team estimated that in one season, an opossum can kill about 5,000 ticks.

So, it’s true that ticks are very good at removing and eating ticks — but not quite as good as the Awesome Possum meme claims. Researchers estimated that one possum could kill about 5,000 ticks in one season — not 4,000 ticks in one year.

And the idea that possums stop the spread of Lyme disease is based on a simple cause-and-effect theory: possums help stop the spread of Lyme disease by killing ticks, which carry the disease.
That’s why we’re calling this one mostly true.