"Remarkably, Crook and colleagues have only recently shown that cephalopods have nociceptors at all. She has also found that octopuses show much of the pain-related behaviour we see in vertebrates, such as grooming and protecting an injured body part. They are more likely to swim away and squirt ink when touched near a wound than elsewhere on their body. Squid, though, may feel pain very differently. Shortly after a squid’s fin is crushed, nociceptors become active not only in the region of the wound but across a large part of its body – extending as far as the opposite fin. This suggests that if it feels pain, rather than being able to pinpoint the location of a wound, an injured squid may hurt all over."