Territory: Lives in a hole or rock crevice in shallow water. Sometimes digs nest in gravel, or uses tentacles to construct a "fortress" out of rocks on the sea bed. These can often be identified by piles of discarded shells lying in the entrance.
Hunting: The octopus hunts at dusk. Crabs, crayfish and bivalve molluscs (two-shelled molluscs such as cockles) are preferred, although it will eat almost anything it can catch. It is able to change colour to blend in with its surroundings, and is able to jump upon any unwary prey that strays across its path. The prey is paralysed by a nerve poison, which the octopus secretes, and the octopus is able to grasp its prey using its powerful tentacles with their two rows of suckers. If the victim is a shelled mollusc, the octopus uses its small teeth to punch a hole in the shell before sucking out the fleshy contents.
If the octopus is trying to tackle a more dangerous opponent, such as a lobster, it first squirts ink into the water to create a smoke screen and confuse the lobster. Then it creeps upon the lobster and seizes it from behind using its tentacles.
Breeding: If you ever see two octopuses apparently holding hands, it probably means that they are mating. The male pumps spermatophores down a specially modified tentacle called the hectocotylus to fertilise the female's eggs.
This can take up to an hour. For about a week afterwards, the female lays clusters of up to 200,000 grape-like eggs inside her nest. She then guards them for four to eight weeks, depending on water temperature, continually touching and cleaning them as she circulates fresh water over them. The eggs hatch into larvae, which look like tiny adults, but which are only 3mm in length. These float in the sea with plankton before coming to rest on the seabed. They grow to maturity in about two years. In the meantime, their mother may well have died from exhaustion, as many female octopuses never recover their strength after going six weeks without food whilst guarding their eggs.Read More: Enemies and Self-Defence