Catching A Ride

The remora is a fish with a structure like a suction cup on top of its head. Using this sucker, it sticks to larger marine creatures—like whale sharks and sting rays—to get a free ride.

But the remora is not trying to get anywhere in particular, explains Brooke Flammang, a biologist at New Jersey Institute of Technology. “The remoras are there for food, friends, and protection,” she says. Traveling with the whale shark protects the remora from predators. It’s also helpful because both remoras and whale sharks eat plankton. When a whale shark swims through a plankton-rich area to feed itself, the remoras catch a meal too. The remoras hop off the shark to do this. Hanging around whale sharks
is also a way for remoras to find mates.

The animals in a phoresy relationship aren’t parasites and don’t harm the larger species. In fact, a remora benefits the whale shark by eating parasites off the shark’s skin!

The remora is a type of fish. It has a structure like a suction cup on top of its head. This helps it stick to larger ocean creatures, like whale sharks and sting rays. That way it gets a free ride!

The remora is not trying to get anywhere in particular, explains Brooke Flammang. She’s a biologist at New Jersey Institute of Technology. “The remoras are there for food, friends, and protection,” she says. Traveling with whale sharks protects remoras from predators. It’s also helpful because both animals eat the same food. Whale sharks swim through clouds of tiny drifting animals called plankton. The remoras can hop off the shark to catch a meal too.

Hitchhiking remoras don’t harm a whale shark. In fact, they’re helpful: They eat pests off the shark’s skin!

Pseudoscorpions are tiny creatures that look like miniature scorpions but aren’t. Like actual scorpions, they’re eight-legged critters called arachnids. Both species also have pincers. But unlike the scorpion, with its stinging tail, pseudoscorpions lack tails.

Pseudoscorpions have previously been spotted hitching rides on insects, mammals, and even other arachnids, like spiders. Last year, researchers in Israel documented a new ride for pseudoscorpions: scorpions! This particular pair have more in common than just appearance. Both are found only in Israel and live in ant nests. The nests give both species shelter and access to prey. For the scorpions, that prey may include ant larvae.

While observing the scorpions at night, under ultraviolet light, the researchers discovered that scorpions were chauffeuring around their look-alikes. Ultraviolet light makes scorpions glow. But the pseudoscorpions appeared as dark patches riding atop the glowing scorpions!

Pseudoscorpions (SOO-doh-skor-pee-uhns) are tiny animals. They look like miniature scorpions, but they aren’t. The two species have many similarities. Both are arachnids, or eight-legged critters. They both have pincers. But scorpions have stinging tails, and pseudoscorpions don’t.

Pseudoscorpions have been spotted riding on insects and mammals. They’ve also been found on other arachnids, like spiders. Last year, scientists in Israel discovered a new pairing. They found pseudoscorpions riding on scorpions!

The two species pictured here have a lot in common. Both are found only in Israel. They both live in ant nests. The nests give them shelter and food to eat. The scorpions may eat the ants’ young.

Scientists were observing the scorpions at night using ultraviolet light. This type of light makes scorpions glow. The pseudoscorpions looked like dark patches riding on the glowing scorpions. That’s how the scientists realized that scorpions were carrying around their look-alikes!

When considering an animal to hitch a ride with, a sloth—the slowest mammal on Earth—might not seem a good choice. But it is for sloth moths. These insects live in sloths’ fur.

Sloths live in the rainforest trees of Central and South America. They leave the treetops only once a week, to climb down to the ground
to poop. Sloth moths lay their eggs in sloth poop. Because the adult moths are flightless, they depend on the sloth to carry them down to the ground.

Once the moth eggs hatch, the young moths—which can fly—jet up to the canopy to settle in a sloth’s fur. At that point, they lose the ability to fly and the cycle begins again.

Sloths may not seem like the best animals to hitch a ride with. They’re the slowest mammals on Earth! But that’s just fine for sloth moths. These insects live in sloths’ fur.

Sloths live in the rainforests of Central and South America. They spend almost all heir time in the treetops. But once a week, they climb down to the ground to poop. Sloth moths lay their eggs in sloth poop. The adult moths can’t fly, so they need the sloth to carry them down to the ground.

The young moths can fly, though. Once they hatch out of their eggs, they hurry up to the treetops. They find a sloth’s fur to settle in. Then they lose the ability to fly, and the cycle begins again.

Hummingbird flower mites feed on the pollen and nectar of flowers. To get from bloom to bloom, the mites walk on their tiny legs. But to get from plant to plant, they prefer air travel—riding inside a hummingbird’s nostrils!

These mites feed on one or two plant species, while hummingbirds stop at many more. So how does a mite know where to hop off? By smell. Once a mite gets a whiff of its preferred plant, it runs out of the bird’s nostril, down the beak, and into the flower!

Choosing a hummingbird to ride is a different story. Mites don’t know where each bird is going, says ecologist Rob Colwell. However, chances are good that if the hummingbird visited the mite’s preferred plant once, it will do so again.

By carrying mites, hummingbirds are aiding the competition, since both animals drink nectar. Colwell has a soft spot for the mites. “These are harmless little freeloaders that have a fascinating life,” he says.

Hummingbird flower mites are tiny insects. They feed on the pollen and nectar of flowers. The mites can walk from bloom to bloom. But to get from plant to plant, they prefer air travel. So they catch a ride inside a hummingbird’s nostrils!

These mites feed on only one or two kinds of flower. But hummingbirds stop at many more. So how does a mite know where to hop off? By smell! Once a mite gets a whiff of its favorite flower, it runs out of the bird’s nostril. It scurries down the beak and into the flower!

How does a mite choose a hummingbird to ride? The insects don’t know where each bird plans to go. But hummingbirds usually visit the same type of plant more than once. So if a mite is already on its favorite plant, it makes sense to hop on any hummingbird that visits!

The mites and hummingbirds both drink nectar. That means the birds are helping their competition. But the mites are small and drink very little. That means there’s plenty left for hummingbirds, says ecologist Rob Colwell. “These are harmless little freeloaders that have a fascinating life,” he says.