TIL Tarantulas and other spiders lack leg extending muscles, and rely on the blood pressure spike from a heartbeat to 'reinflate' the leg back to its extended position. This is why spiders curl up when they die.

http://animagraffs.com/tarantula/



Submitted February 13, 2015 at 12:21AM by ProjectGO http://www.reddit.com/r/todayilearned/comments/2vofva/til_tarantulas_and_other_spiders_lack_leg/