Assuming you mean they raise their abdomen in the air... It's commonly seen in newly-hatched Spiders. In order to disperse after hatching, they raise their abdomens in the air, and eject a line of silk. The 'spiderlings' are so light, that the slighest breeze will lift the silk thread and the spider often high into the air - and carry them away to start their new independent life.
A very small one
They make spider webs, which some sticky thing that makes the fly stick to it.
Up a bum
fishy fandangoo
you look up ur bum
Spiders eat most of an insect. Some spiders are capable of chewing up the entire body of whatever it has caught, flooding the chewed up mass with digestive fluid, and then sucking up the digested food. Other spiders are not capable of chewing up the exoskeleton of a prey item, so they inject digestive fluids into the body, let the contents of the exoskeleton digest, and then suck that up.
BUM HOLES
you stick a chicken up your bum bum
stick you finger up you bum!
Stick it up your bum
stick it up your bum
Stick your finger up your bum and your bum will tell
Alcohol and Robotussin.
You stick fork up camal bum
stick your hand up your bum and say buga woga
The aim is to stop asking this question and stick it up your bum
take a laightsaber, stick up his bum hole and run away hahahahaha
it means wen u stick ur toes up some1s bum