More impressive still, an octopus can change color in less than a second. Chameleons are just dead-boring compared to octopuses. In its den, an octopus will often simply lie hidden, its arms coiled, before unrolling one to snag a passerby with the suckers at the tip. While swimming, its preferred attack posture is to parachute gently down with all eight arms outstretched and envelop its prey in the web connecting the arms. Having wrapped up its victim, an octopus holds it against its underside and bites it with a retractable, parrotlike beak.
Octopuses also crawl over reefs, probing with their arms for hidden prey.
The salivary glands of all octopuses secrete a chemical that helps disable its prey and breakdown its muscle tissue. In at least one species, Australia's blue-ringed octopus, the secretion contains a neurotoxin that constitutes the deadliest venom known in nature, capable of killing an adult human in minutes. However, these octopuses do not bite humans unless handled or disturbed. The poison is used as a coup de grace on the blue ring's prey, allowing the octopus to eat at its leisure. Octopuses as a group act like leisurely, almost lazy animals.