There's something oddly soothing about hearing David Attenborough say the words, "soft, slumpy legs." Almost like he's talking about Winnie the Pooh, rather than a carnivorous worm that eats its prey alive.
How does the velvet worm trap creatures long enough to slowly consume them? In the video, you can see it spraying out a sticky, quick-hardening slime that engulfs a cricket and renders it motionless. The trick, according to some cool research written about by bloggers Brian Switek and Scicurious, is that the slime is 90% water. Once exposed to air, the water evaporates out, leaving behind an ever-tightening net.