Octopuses, squids and their cephalopod cousins have haunted the human imagination for centuries. Their long, unfurling arms and temperamental behavior have inspired legends, from the Kraken of Norse mythology to the giant Japanese Akkorokamui that supposedly lurks at the bottom of the ocean, waiting to swallow ships and whales whole.

Cephalopods sit apart from other invertebrates because they have evolved with highly complex nervous systems that give their arms a mind of their own, making the creatures star attractions at many aquariums. They are brilliant at camouflage despite being colorblind, have a talent for opening jars and shape-shifting, and can communicate in their own Morse code.

For Cephalopod Week, which runs from June 21 to 28, here are eight of our favorite facts about cephalopods, to make them even more embraceable.

Scientists have a hard time studying octopuses. The animals often have to be kept in separate tanks so they don’t kill each other. But when a group of researchers gave octopuses a dose of the party drug ecstasy last year, the creatures suddenly became more social. They slid up to the edge of their tanks and even reached out to interact with neighboring octopuses.