We've all done it. And it turns out, so has a certain jellyfish!
The Cigar Jelly is a hydrozoan jellyfish which reaches about 8 cm (5 in) across. It's found in the central and eastern Atlantic Ocean and the Mediterranean Sea, and it or others like it have also been seen near Australia and the like.
They get the name from their sleeping habits. This nocturnal species likes to spend its days rolled up into a cigar shape, tentacles carefully retracted into its body. Come the night and it can unroll and set off catching small prey with tentacles that can apparently reach up to 10 metres (33 ft) long when fully extended.
All of which raises the question: do jellyfish dream of gelatinous sheep?