An Immense World: How Animal Senses Reveal the Hidden Realms Around Us

by Ed Yong

Science-fiction authors like to conjure up parallel universes and alternate realities, where things are similar to this one but slightly different. Those exist!

Male mice produce a pheromone in their urine that makes females especially attracted to other components in their odor; this substance is called darcin, after Pride and Prejudice’s male hero.

Taste is reflexive and innate, while smell is not.[*29]

It’s ironic that we associate taste with connoisseurship, subtlety, and fine discrimination when it is among the coarsest of senses. Even our ability to taste bitter, which warns us of hundreds of potentially toxic compounds, isn’t built to distinguish between them. There’s only one sensation of bitter because you don’t need to know which bitter thing you’re tasting—you just need to know to stop tasting it.

In 2014, evolutionary biologist Maude Baldwin showed that some of the earliest songbirds regained their sweet tooth by tweaking a taste receptor that normally senses umami into one that also senses sugar.

In vertebrates, the taste system is mostly wired to the hindbrain, which controls basic vital functions. The smell system is hooked up to the forebrain, which controls more advanced abilities like learning.

Mantis shrimps throw punches like humans throw opinions—frequently, aggressively, and without provocation.

“Surprisingly Long Survival of Premature Conclusions About Naked Mole-Rat

In a refreshing act of academic straight talk, he and Bakken published their results under the title “Cooler Snakes Respond More Strongly to Infrared Stimuli, but We Have No Idea Why.”

Mark Rutland, who led the study in which volunteers distinguished between ridges that differed in height by 10 nanometers, said that “if your finger was the size of the Earth, you could feel the difference between houses [and] cars.” That’s true, but only if you dragged your planet-sized digit down the street—an act that, ironically, would be rather insensitive.

This happened within 20 generations, making the “flatwing” crickets one of the fastest cases of evolution that has ever been documented in the wild. The newly silent males are undetectable to Ormia, but also to females. The silent males are reduced to loitering around the few males who can still sing, in the hopes of sneakily mating with approaching females. They also still go through the motions of singing, rubbing their wings together as if they could still thrrrrp away.

Females almost always go for males who embellish their whines with chucks over males who merely whine. The chucks are so desirable that if a male is reluctant to make them, a female will sometimes body-slam him until he does.

(This is also why devices that claim to repel pests with ultrasound don’t really work: Their range is far too limited to be of much practical use.)

Echolocation differs from the senses we have met so far, because it involves putting energy into the environment.

dilemma: We might never know what it’s like to be a bat, but Kish can explain what it’s like to be Kish.

At the time of writing, magnetoreception remains the only sense without a known sensor. Magnetoreceptors are “the holy grail of sensory biology,” Eric Warrant tells me. “There may even be a Nobel Prize in finding them.”