Octopuses are remarkably intelligent animals. They have a larger brain for their body size than all other animals apart from birds and mammals. They exhibit high-order cognitive behaviors including tool use and problem solving. Some captive octopuses learned to shoot jets of water at aquarium light switches to turn them off. Others have learned to unscrew jar lids to get at food.
A recent analysis of underwater imaging has shown that octopuses are increasingly using discarded bottles, cans, and other human-generated litter as shelter or as a place to lay eggs.
The research documented 24 species of octopus sheltering inside glass bottles, cans, and even an old battery. Some buried themselves under a mixture of bottle caps and seashells. Others even carried plastic items around while walking on just two tentacles to disguise themselves from predators.
The octopuses showed a preference for unbroken items and for darker or opaque containers. Normally, octopuses make use of natural shelters such as seashells. Whether they are making use of litter simply because there is so much of it around or because there is an increasing lack of natural items is not clear.
As with all other aspects of the growing problem of litter in the oceans, this new trend is not a good one. Sheltering or laying eggs inside discarded tires, batteries, or plastic items has the potential to expose octopuses to heavy metals and other harmful chemicals.
Octopuses are intelligent and resourceful animals, and they will use whatever they have at their disposal to continue sheltering or moving around with protection from potential predators.
Photo, posted May 13, 2014, courtesy of Elias Levy via Flickr.