WEBVTT - Why Are Opossums Awesome? 0:00:02.040 --> 0:00:07.200 Welcome to brain Stuff from How Stuff Works. Hey, brain Stuff, 0:00:07.240 --> 0:00:10.680 Lauren Vogelbaum. Here. If you live in North America, you've 0:00:10.680 --> 0:00:14.560 probably seen a Virginia a possum classification to Delphis Virginiana. 0:00:15.280 --> 0:00:18.160 Maybe the unfortunate creature was dead on the road, or 0:00:18.200 --> 0:00:20.360 maybe it was very much alive on your porch eating 0:00:20.360 --> 0:00:22.720 garbage in the middle of the night. But in either 0:00:22.800 --> 0:00:26.560 case you might have thought, oh, gross, a possum. But 0:00:26.880 --> 0:00:30.360 you would have been off base on several counts. First 0:00:30.360 --> 0:00:34.080 of all, possums live in Australia and are also a marsupial, 0:00:34.120 --> 0:00:36.120 which means they raise their young in a pouch like 0:00:36.159 --> 0:00:39.040 a kangaroo, but they are a completely different species. And 0:00:39.080 --> 0:00:41.560 the animal currently snuggling with a half eaten bag of 0:00:41.600 --> 0:00:43.680 Doritos at the bottom of a curbside trash can in 0:00:43.720 --> 0:00:48.480 North Carolina, which is correctly an a possum. We spoke 0:00:48.479 --> 0:00:51.600 with Richard Osfeld, senior scientist at the Caree Institute of 0:00:51.640 --> 0:00:55.319 Ecosystem Studies in Millbrook, New York. He said, folks get 0:00:55.400 --> 0:00:58.320 very confused about this. I've had people tell me triumphantly 0:00:58.360 --> 0:01:01.400 that they discovered building plans for possum nest boxes and 0:01:01.400 --> 0:01:03.640 that they planned to install dozens of them to encourage 0:01:03.640 --> 0:01:06.760 opossums to multiply on their property. But when I looked 0:01:06.800 --> 0:01:09.520 up the plans, they were designed for brush tailed possums 0:01:09.520 --> 0:01:14.959 in Australia, completely useless for apossums in North America. So 0:01:15.360 --> 0:01:19.040 with that part settled, opossums aren't that gross, even if 0:01:19.080 --> 0:01:21.720 they wouldn't mind taking that multipad tie from the back 0:01:21.760 --> 0:01:24.520 of your refrigerator off of your hands. They may look 0:01:24.560 --> 0:01:27.560 a little creepy, what with that long, hairless, prehensile tail, 0:01:27.840 --> 0:01:31.039 the mouthful of haphazard teeth, and the beady eyes, but 0:01:31.080 --> 0:01:34.559 apossums are the fastidiously groomed and most likely disease free 0:01:34.680 --> 0:01:39.880 wildlife heroes of your neighborhood. It's a common misconception, possibly 0:01:39.880 --> 0:01:43.560 prompted by their bumbling swagger, that apossums often carry rabies 0:01:43.640 --> 0:01:46.680 or a distemper. In fact, they rarely get these diseases 0:01:46.720 --> 0:01:49.520 because their body temperature is too low to make them susceptible. 0:01:50.200 --> 0:01:53.520 Not only do apossums not carry these diseases, the presence 0:01:53.520 --> 0:01:55.600 of an opossum in your yard is your best bet 0:01:55.640 --> 0:01:59.760 for combating lime disease. A two thousand nine study explored 0:01:59.800 --> 0:02:02.840 whether black legged ticks. The disease vector for lime disease 0:02:03.240 --> 0:02:07.920 might be regulated by wildlife that they parasities of fifteen 0:02:08.000 --> 0:02:11.400 forest dwelling mammals and ground nesting birds. Opossums were the 0:02:11.480 --> 0:02:14.120 only ones to destroy the vast majority of all of 0:02:14.160 --> 0:02:16.320 the black legged ticks that tried to feed on them. 0:02:16.560 --> 0:02:22.400 Over Ostfeld, who co authored the study, said, our calculations 0:02:22.440 --> 0:02:25.320 indicated that a single opossum is capable of killing several 0:02:25.360 --> 0:02:28.200 thousand larval ticks per week during the late summer peak. 0:02:28.800 --> 0:02:31.320 We also know that of those ticks that do successfully 0:02:31.320 --> 0:02:34.040 feed on an opossum, only a small fraction will become 0:02:34.040 --> 0:02:38.040 infected with the lime disease bacterium, so apossums are protective 0:02:38.080 --> 0:02:42.760 in two ways, killing ticks and preventing infection. A study 0:02:42.800 --> 0:02:45.560 by the same research team published in July ten in 0:02:45.560 --> 0:02:48.320 the journal Ecology found that tick born disease risk was 0:02:48.400 --> 0:02:52.680 reduced in areas where opossums were present. For an animal 0:02:52.720 --> 0:02:55.160 that does more than its fair share of hobbling into 0:02:55.160 --> 0:02:57.680 traffic and is known for flopping over like a corpse 0:02:57.680 --> 0:03:00.919 at the merest whiff of danger, apossums are perhaps surprisingly 0:03:00.960 --> 0:03:04.799 intelligent to begin with weak eyesight at a nocturnal nature. 0:03:04.840 --> 0:03:07.560 Both contribute to the fact that you're probably more familiar 0:03:07.560 --> 0:03:09.359 with the side of a dead apossum than a live one. 0:03:10.040 --> 0:03:13.640 In addition, their primary defense mechanism, playing dead is almost 0:03:13.760 --> 0:03:17.480 entirely involuntary, a reaction to extreme stress that leaves the 0:03:17.520 --> 0:03:19.520 apostum in a coma for a few minutes to a 0:03:19.560 --> 0:03:22.640 couple of hours, and a comatose apossum can take a 0:03:22.639 --> 0:03:25.959 beating that would kill other animals their size. This, then, 0:03:26.200 --> 0:03:28.480 is a great strategy if your mortal enemy is a bear, 0:03:28.800 --> 0:03:32.360 but not so great if it's a toyota. So if, 0:03:32.520 --> 0:03:35.240 for example, your dog corners an opossum one night in 0:03:35.240 --> 0:03:38.480 the backyard, don't worry. The apostum may hiss and show 0:03:38.520 --> 0:03:41.240 its teeth in an attempt to look scary because it's frightened, 0:03:41.400 --> 0:03:43.240 but the last thing it wants is to tangle with 0:03:43.280 --> 0:03:46.200 your four legged friend. It will invariably lay down and 0:03:46.240 --> 0:03:49.760 play dead until the threat gets bored and passes. Apossums 0:03:49.800 --> 0:03:53.360 are non aggressive, docile creatures, far more afraid than they 0:03:53.360 --> 0:03:58.480 are to be feared, and they're also fastidiously clean. Like cats, 0:03:58.480 --> 0:04:01.480 apossums are constantly grimming themselves with their paws and tongue, 0:04:01.800 --> 0:04:04.200 partly in order to make sure they're parasite free, but 0:04:04.280 --> 0:04:06.960 also to keep themselves cool. They lack sweat glands, so 0:04:07.040 --> 0:04:10.240 grooming is like apossum air conditioning, and they do it 0:04:10.280 --> 0:04:14.920 to keep themselves smelling like well nothing. As we've established, 0:04:14.920 --> 0:04:17.479 apossums aren't great at protecting themselves in a standoff with 0:04:17.520 --> 0:04:20.640 a predator, so it behooves them to stay odor neutral. 0:04:21.320 --> 0:04:23.560 Part of the reason apossums have the reputation for being 0:04:23.600 --> 0:04:26.440 smelly has to do with one other defense mechanism, the 0:04:26.480 --> 0:04:30.200 smell of death. Once an opossum goes into its theatrical coma, 0:04:30.400 --> 0:04:32.800 if a predator continues to mess with it, the opossum 0:04:32.880 --> 0:04:35.640 may excrete a smelly mucus from glands in its anus. 0:04:36.200 --> 0:04:39.360 This has been a signal, Hey, this apossum is definitely dead, 0:04:39.560 --> 0:04:42.360 and possibly so entirely dead that it'll make you sorry 0:04:42.400 --> 0:04:46.600 you ate it. Speaking of, apossums are really smart about 0:04:46.600 --> 0:04:49.520 what they eat, because it turns out they have great memories. 0:04:50.120 --> 0:04:52.600 Once an apostum tastes a chemical that doesn't agree with it, 0:04:52.839 --> 0:04:54.640 it will remember and avoid the smell of it for 0:04:54.680 --> 0:04:58.000 a year afterwards. Though apossums are immune to some things, 0:04:58.000 --> 0:05:02.560 that would poison other mammals, including most snake venoms. Apossums 0:05:02.560 --> 0:05:07.239 are biologically fascinating, which led to some confusion among earlier 0:05:07.279 --> 0:05:10.360 Europeans in the New World. Their story was the male 0:05:10.400 --> 0:05:13.720 opossum made it through the female apossums snout, which led 0:05:13.760 --> 0:05:16.880 to her sneezing out her babies into her marsupial pouch. 0:05:17.560 --> 0:05:21.479 Of course, this is not scientifically accurate, but apossums definitely 0:05:21.520 --> 0:05:24.640 do things a little differently. First of all, a male 0:05:24.680 --> 0:05:27.359 apossum has a forked penis, but it's not meant for 0:05:27.360 --> 0:05:30.680 the female's nostrils. Female apossums have a double vagina and 0:05:30.760 --> 0:05:35.160 twin uteri. Apostsum embryos developed for about thirteen days until 0:05:35.160 --> 0:05:37.400 they're large enough to migrate down the birth canal and 0:05:37.440 --> 0:05:40.520 emerge about the size of house flies to continue developing 0:05:40.560 --> 0:05:43.680 in the mother's pouch. Although dozens of them will be born, 0:05:43.760 --> 0:05:46.880 the mother only has thirteen teats, so that's probably how 0:05:46.880 --> 0:05:54.599 many will be able to survive into adulthood. Today's episode 0:05:54.640 --> 0:05:56.960 was written by Jescelyin Shields and produced by Tyler Clang. 0:05:57.360 --> 0:05:59.240 Brain Stuff is a production of I Heart Radio's How 0:05:59.240 --> 0:06:01.200 Stuff Works. For more in this and lots of other 0:06:01.240 --> 0:06:04.400 animal tails. Visit our home planet, how stuffworks dot com 0:06:04.440 --> 0:06:06.600 and for more podcasts. 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