Probably one of the greatest mysteries of all time regards the works of the subconscious mind. We already know that every human being dreams and we’ve also come to find that our favorite pets (dogs and cats) dream too, so the next question is… do all animals dream?

A quick look at Aristotle’s work regarding animals tells us that “Almost all other animals are clearly observed to partake in sleep, whether they are aquatic, aerial, or terrestrial.” Although he lacked the technology to test his theory, he was actually right – sort of.

Indeed it’s true that most of the animals out there dream (even octopus, but we’ll get to that later). However, every animal species has its own way of dreaming. In 1965, French scientists proved that cats dream just like us when they removed a few cells from their brain which were responsible with lying still while sleeping. Every time the cats started dreaming, they were running around or acting just as if they were capturing their prey – which means that their dreams are based on visual memories, just like ours. The same goes for dogs, mice and many other creatures. But not for them:

Here’s a busted myth: zebra finches aren’t born with melodies in their head and they don’t sing sandomly either. When studies at the University of Chicago proved that, researchers also found something interesting. As they were studying the finches’ neurons acting in a specific way so they would sing the same song, they discovered that the exact same movements occured when they were asleep too! This means that these birds, as well as others, aren’t dreaming of images, but of sounds.

As for cephalopods (squid, octopuses, cuttlefish), studies proved that they also dream, but only see certain colors they notice while they’re awake.