Veined octopus in a giant clam shell, Sulawesi Sea, Indonesia

Need some 'shell'ter?. World Octopus Day

Don't blame yourself if you are not sure what you are looking at. The veined octopus, also known as the coconut octopus, is one of the smartest animals on Earth, and has an exceptional talent for building deceptive shelter from seashells and coconut shells. If you peek inside, you may notice some arms covered with circular suction cups; octopuses have eight of these limbs, which is where their name originates from. 'Októpus' is a Greek word, meaning 'eight footed'. The arms, lined with suckers, have clusters of neurons in them, which make them particularly sensitive. Each arm—attached to the conical head—can be used separately, allowing the octopus to solve often complex tasks. Octopuses can match the colour—sometimes even the texture—of their environment, which might be another reason why you don't spot them easily.

There are many more reasons to celebrate these intelligent and fascinating animals! Today is World Octopus Day, making it an excellent occasion to watch a documentary about them. In case you need guidance, you can start with 'My Octopus Teacher.'