The reason octopuses and squids have eight arms is that it allows them to do all kinds of helpful things! For example, octopuses are able to detach one of their arms from their body if the arm is caught by a predator! The arm continues to move even after it’s disconnected from the octopus’s body, which confuses the predator while the octopus make his or her escape! (The missing arm then grows back over time.)
The eight arms also help octopuses and squids to move around at the bottom of the ocean floor. Some recent science has also shown that octopuses may sometimes use two of their limbs more like legs while the other six of them are more like arms. This can help the octopus to continue walking while using its other six limbs to camouflage itself into another shape! (Sounds like having eight arms can be pretty handy!)
ExplorationMake a pet octopus!
Using just a paper bag, a rubber band, and some imagination, you can make your very own eight-armed head-footed octopus at home!
First, stuff a paper bag about half way full with some scrap paper that is crumpled up into a ball. Then, tie the end of the bag closed with the rubber band. Now, turn the bag upside down so that the stuffed end is on top. This is going to be your octopus!
Cut the paper below the rubber band into eight strips to create eight legs. Then decorate your octopus's head with eyes and a mouth! If you have a couple of paper bags, you can even make an entire octopus family! And don't forget to give each octopus a name when you're done!
Sources & links
Kane, Daniel B. “Octopuses ‘walk’ on 2 arms to get by predators.” Tech & Science. 25 Mar. 2005. MSNBC. 24 Dec. 2010 Seibel, Brad. “Octopuses, Squids, and other Cephalopods.” Investigate the Giant Squid: Mysterious Cephalopod of the Sea. Scholastic Teachers. 24 Dec. 2010 “Octopuses.” Glossopedia. Globio. 24 Dec. 2010