This story was updated on October 22, 2018.
It's nearly Halloween, the time of year when no one could blame you for believing in ghosts. These otherworldly spirits bring to mind elusive shapes, pale colors, and strange sounds.
And some wild animals with these very same traits have an equally spooky reputation. (Read "How Cats, Rats, Bats, and More Became Halloween Animals.")
For instance, lemurs of Madagascar make haunting territorial calls that once reminded people of "ghosts or spirits living in the forest,” says Chelsea Feast, lemur expert for the Tennessee Aquarium. The word “lemur” comes from the Latin word for ghost. (Listen to some lemur sounds.)
Black and white ruffed and red ruffed lemurs, both critically endangered, make calls that “almost sound demonic,” Feast says.
Another ghoulish trait is in their eyes. A special film on a lemur’s eyes called the tapetum reflects light and thus glows, like a cat’s eyes. Some have very orange—and some would say eerie—reflections, Feast says.
So does the endangered aye-aye, a large, nocturnal lemur with a witch-like middle finger that the animal uses to find insects.
“It was considered a bad omen if you saw an aye aye,” and at one time people killed them on sight, she adds.
That's because the 50 known species of ghost sharks aren’t sharks.
They’re chimeras, a type of fish that branched off from sharks about 400 million years ago. (Also: "Watch an Amazing 'Ghost Octopus' Discovered in the Deep Sea.")
The deep-dwelling creatures look more like Frankenstein’s monster than ghosts, with sensory organs dotting their skin like stitches. (The male's forehead also sports a retractable sex organ, a clasper to help him hold onto that lucky Bride of Frankenshark.)
Male ghost moths or ghost swifts “do a funky little dance” to attract the ladies.
The insects "appear out of nowhere, popping up from the ground like meerkats, going back and forth and then going back down,” Burgess says.
“They very much imitate our impression of how ghosts appear and disappear,” Burgess says. Not to mention Hepialus humuli humuli males' white color makes their name spot on.
Meanwhile, back in Madagascar, scientists recently discovered a pale gray snake and named it Madagascarophis lolo, the latter of which is Malagasy for “ghost.”
The reptile, called luu-luu, had evaded detection for a long time—hence its name.
Halloween bonus: luu-luu is part of a group called cat-eyed snakes, named for their feline-like pupils.
All seven species of ghost frog live in South Africa, but these little amphibians lack a ghastly pallor.
Instead, they’re regular froggy green and likely get their moniker from the Skeleton Gorge area of Cape Town's Table Mountain, home to one critically endangered species.
Skeleton Gorge has fast-moving streams and rivers, and ghost frogs “have really big suction cups so they can hold on to rocks,” says Burgess. Tadpoles even have sucker-like mouths to withstand rapid currents.
Maybe instead of ghosts, they should be called cling-ons.
This story was originally published October 28, 2017.