To hear them today, Cocroft simply uses a cheap speaker and a digital recorder connected to a clip-on microphone that a guitarist might use. With this kit, he spends his spare time prospecting for vibrations, miking random stems, leaves, and branches in nearby parks, or even in his backyard.

So how does the worm know if a given sensation comes from its own movement (reafference) or someone else’s (exafference)? How does it know if it is touching something, or if it has been touched? Similarly, if a fish’s lateral line detects flowing water, is that because something is swimming toward it, or because it is itself swimming?

This is how all animals see—using light-sensitive proteins that are actually modified chemical sensors. In a way, we see by smelling light.

There are two major groups of animal photoreceptors, known as ciliary and rhabdomeric. Both use opsins, but they function in very different ways.

“They move finished and complete, gifted with extensions of the senses we have lost or never attained, living by voices we shall never hear,” wrote the American naturalist Henry Beston. “They are not brethren, they are not underlings; they are other nations, caught with ourselves in the net of life and time, fellow prisoners of the splendour and

You could envision yourself with webbing on your arms or insects in your mouth, but you’d still be creating a mental caricature of you as a bat. “I want to know what it is like for a bat to be a bat,” Nagel wrote. “Yet if I try to imagine this, I am restricted to the resources of my own mind, and those resources are inadequate to the task.”

To stand any chance of knowing what it is like to be another animal, we need to know almost everything about that animal. We need to know about all of its senses, its nervous system and the rest of its body, its needs and its environment, its evolutionary past and its ecological present.

the Jahai can name smells as easily as English-speakers can name colors.

As we push animals away, we get used to their absence. As the problem of sensory pollution grows, our willingness to address it subsides.