Putting lab rats in a maze  is a bit of a science cliche.

And for good reason! Scientists really do design a lot of experiments that  involve putting rats in mazes.

Watching how they handle being  plopped in an obstacle course reveals a lot about how they see,  think, and navigate their surroundings. It’s so illuminating that scientists can’t seem to stop themselves  from designing all sorts of little escape rooms for  their animal test subjects. So here are five times scientists  put animals in ridiculous situations just to see what they would do. [Intro music] You’ve likely heard that bats use  echolocation to help them navigate.

They can find food with ease and fly  around with excellent obstacle avoidance. All thanks to a fairly simple concept. The bat makes a noise, like a chirp or click, and the sound waves bounce off  the things in their environment, such as any tasty insects hovering nearby.

The bat listens for the echo and  uses that to locate the tasty insect. And also any neighbors or predators  that it doesn’t want to bump into. It’s easy to imagine how this works if there are only a few flying  insects and one hungry bat.

But what about when there are  tens of thousands of insects, and hundreds of bats that  are also all echolocating? How do the bats keep all that  sound information straight? To figure it out, scientists added some  infrastructure to a natural corridor with a lot of bat traffic.

Between these bats’ roost and feeding grounds, the researchers installed four panels with artificial leaves that  were attached to conveyor belts. They tracked how these bats  changed their flight speed when the artificial leaves were either moved  with the bats’ direction of flight or against it. They discovered that the  bats flew slower or faster than they did in static surroundings,   and their speed change depended on  the way the echo frequencies shifted.

This means that bats don’t  just listen for the time delay between their noise and an echo. They also listen for Doppler shifts. Doppler shift is a change in frequency that occurs when a signal source and the  observer are moving relative to each other.

When the thing that makes  the sound moves towards you, the sound is pitched higher as the  sound waves get squeezed together. Then as it moves away, the pitch is lower because the sound waves stretch  out as they travel to you. Like how the siren of an ambulance  changes pitch as it speeds past you.

So the idea is that if the leaves move in  the same direction as the bats’ flight, their echo would be pitched down. That could make the bats think they’re  flying slower than they thought they were, and they might speed up to compensate for that. And vice versa, if the leaves move  against the bats’ flight direction, their echo would pitch up, and the bats  might think they’re flying too fast!

The researchers want a bigger data set  before drawing too many conclusions. But they believe this obstacle  course could provide evidence   that bats gauge speed based on acoustic flow, or how much the sound waves change as they move. Acoustic flow is similar to optic flow, where objects become visually  distorted as you move.

Glancing out a car window gives your  brain a pretty good sense of how fast   you’re moving based on how much the objects blur. Many animals rely on optic flow to  help navigate and gauge their speed, so researchers are keen to understand how other  senses contribute to these skills, as well. Speaking of speed, isn’t it impressive how fast cockroaches   can scurry without tripping  over all those little feet?

Despite their smallness, they regularly  clamber over relatively enormous obstacles, often to the displeasure of any humans around. Researchers wanted to learn more  about their epic parkour skills,   so they built their cockroaches some treadmills. The treadmills were spherical so  that the researchers could track   the bugs as they traveled long  distances in multiple directions.

It was additionally studded with various  obstacles, in both sparse and dense arrangements. Then the researchers turned  cockroaches loose on the treadmill, and settled in to see what they’d do. Why does that kind of remind me of Maze Runner?

This experimental design was really clever because most maze-type experiments are  limited by however big you can make your maze. Even if you substitute a standard  treadmill, it’s hard to add obstacles. The spiky obstacle sphere  solves both these problems!

And, it lets the researchers track the cockroaches over long distances and for  relatively long periods of time,   all within a pretty compact space. For example, one of the bugs spent 25  minutes navigating a cluttered environment, and traveled more than 67 meters, which  is about 1,500 times its body length. Extended data collection like  this tells the researchers about the ways cockroaches move  during long distance journeys.

They found that the cockroaches adapt  their movements to the environment. Instead of just walking, they also climbed, rolled  through gaps, and occasionally just... paused. Presumably, they were in  great shape afterward as well.

While the cockroaches were  having fun on their treadmills, some jumping spiders were playing video games. Sort of. But for science!

The researchers leading this  study wanted to understand how well jumping spiders can see. And the experiment they  designed was pretty bonkers. They glued little magnets to  the jumping spiders’ heads, then connected a little pin to the magnet, like a tiny leash to keep them  tethered to the experimental apparatus: a small polystyrene ball.

Next they plopped the tethered spider into  basically a spider-sized IMAX theatre, with projections of a virtual  reality world everywhere in sight. Okay now this one reminds me of The Matrix. To navigate the Matrix—I mean the virtual space— the spider would move its feet  and rotate the little ball, which basically served as a tiny treadmill.

Or a computer mouse trackball. As they rotated the ball, the  projected image would shift, in pretty much the same way  VR headsets work for humans. And, also pretty much like humans, the spiders seemed to understand what the VR world   represented and were able to navigate it  the same way they would the real world.

In other words, the researchers  didn’t find many differences between the way spiders behave in  the real world and virtual worlds. Things like how active they were  and whether they sought out dark   hiding places were consistent from  the real world to the virtual one. Those experiments laid the groundwork for follow up experiments to probe the  details of jumping spiders’ vision.

For example, more recently a research  team from the University of Cincinnati projected dots of color  onto a colorful background. They were watching to see if the spiders attempted   to chase the colored dots  through the VR landscape, indicating the spiders’ ability  to perceive different colors. So far their preliminary results show  that jumping spiders can distinguish between ultraviolet and green, and some  of them can also tell red and green apart!

The ability to learn their  colors could be pretty important for whenever the jumping spider Neo needs  to choose between the red and the blue pill… VR for spiders is a pretty  high-tech piece of science, but scientists are still  trying to find good solutions for much more low-tech problems, like bottlenecks. A “bottleneck” is a situation  where a lot of objects, animals, or people are trying to  travel through a very small space at around the same time, frequently leading to jams. Bottlenecks are a nuisance for concert-goers,  coffee beans, and sheep, among others.

So for a lot of practical reasons,  bottlenecks are a popular research topic. Sheep are especially good bottleneck-ers  because large groups of sheep tend to get stuck when trying  to go through small barn doors, usually because they’re all in a hurry  to get the food on the other side. But unlike people, they aren’t  influenced by customs of politeness.

Lest you be worried about the  sheep-jams, they rarely hurt each other. Must be all that cushy wool! One common sheep-versus-doorway experimental setup involves placing an object  near the front of the doorway.

The sheep have to navigate around the object, so it slows them down and helps them get  through the door without getting stuck. In one of these experiments, the researchers placed a  cylindrical concrete drainpipe with a diameter of 114 cm  in front of a 96 cm doorway. Their test subjects were groups of 80 to  90 sheep, all of them about the same size.

They placed the barrier at distances  of 60, 80, and 100 cm from the door. When the barrier was only 60 cm away, the group was slower than it  was when there was no barrier. But, compared to no barrier at  all, the group got through faster when there was a barrier at 80 or 100 cm.

So when put in the right spot, adding an obstacle  in front of the door improved sheep traffic flow! The strategy works for sheep because they have to slow down  to navigate around the barrier. That prevents pile-ups from occurring at  the door, and keeps traffic moving along.

Excellent results! Now let’s do this at  concerts and sporting events, too please! Unfortunately it’s not quite  that simple for people.

Because while sheep are universally  pretty rude to each other, humans exist on a spectrum from  very polite to incredibly impolite. And that competitive aspect,  or any element of panic, might affect bottleneck behavior more  than a well-placed barrier would. So we’ll just have to keep  researching other methods to keep human traffic flowing smoothly.

Ants, on the other hand, are  great in evacuation scenarios, because they’re so good at cooperating! To put those cooperation skills to the test, scientists built an obstacle course  containing three chambers connected by two narrow doors and gave their tiny  test subjects a T-shaped puzzle piece to maneuver through it. What is this... an obstacle course for ants?

If you’ve ever tried to move  a sofa into a new apartment, you probably know how those ants felt. If you’re wondering how the researchers  convinced the ants to take up the challenge, the puzzle piece was basically marinated  in stinky cat food and canned tuna. This inspired the ants to get their puzzle  piece back to the colony at all costs, because who doesn’t enjoy catfood stink?

But here’s the punchline: The researchers gave the same  task to a crew of humans. And the ants were way better  at solving the puzzle. The humans’ puzzle piece,  by the way, was unmarinated.

Because if you don’t mind some  very unscientific speculation, the results would have been  very different for humans forced to maneuver a giant  T-shaped piece of catfood stink. Taken together, the results of the research suggests that the ants were using a  kind of short-term collective memory. Okay now this is reminding me of the Borg!

On the other hand, the humans have to  talk it out, reason with each other, and align on a strategy in  order to solve the puzzle. While ants just do what everyone else is doing. This works for the ants because as they  collectively pull an object in a single direction, the group continues to move in that direction, even when they hit a corner.

This persistence lets them gradually work  the puzzle piece through the opening. Interestingly, this kind of wordless  teamwork doesn’t seem to help humans. When humans are given a similar task  and told not to talk to each other, they tend to pick the most  direct-looking way out of the puzzle, even if the indirect way is more efficient.

To be fair, evolution has  let ants excel at cooperation and problem solving through  large group mobilization. Even though they can’t really comprehend a  problem in its entirety, they don't need to! They just use short-term memories of  collective group motion to solve the puzzle.

All of these examples revealed insights about animal sensing, behavior, and navigation. That just goes to show the huge potential that mazes and obstacle courses have for helping  scientists understand the ways animals think! There’s no telling what kind of animal  escape rooms scientists might concoct next.