Do octopus legs get tangled?
An octopus leg has hundreds of suckers that instinctively seize almost anything it comes into contact with, yet the animal’s eight limbs never grip each other or get tangled up. To understand how and why, scientists in Israel amputated an octopus limb (giving an assurance that it would grow back later) and put it in a tank, where it remained active for more than an hour. During that time, it grabbed at pretty much everything, including a skinned octopus arm, while ignoring its original owner and other octopuses, as well as amputated limbs with the skin still on. The researchers think that a chemical in octopus skin acts as a sucker-repellent, and that this same chemical stops a live animal tying itself in knots. They hope to use this discovery to build better bio-inspired robots that can shape-shift like an octopus. Helen Pilcher