This is also a common problem in dogs, it can occur in cats but far less often. Pets do this because there is an irritation/itch around the anal area - they will rub there bum along the ground or lick at excessively. There are three common reasons pets will do this.
1. Fleas running around the area can cause this reaction - ensure you have a good continuous flea control program for all the pets in the household.
2. Segments of the common tapeworm can crawl around the area causing irritation. These look like a small cucumber seed; they are actually a sack of eggs that can move. They want to get ingested by a flea, the pet then ingests the flea and their life cycle continues. So you must control fleas and worm your pets when you see evidence of the tapeworm. The problem is you can worm your pet and kill the tapeworm but then they ingest a flea carrying the tapeworm and they get it back again.
3. Anal glands are two sacs at the side of your petís anus - their position can be seen in the image shown. They are there as part of your pets communication /marking behaviour. The secretion is very smelly,- dogs sniff each otherís bums to get a whiff, it is thought it is a recognition system when dogs were part of packs. They also can be used to mark their territory back in the day when dogs were wild.
These glands can become impacted - meaning the secretion is not being discharged (which usually happens when they defecate) the secretion builds up causing pressure which your pet trys to relieve by rubbing it bum along the ground - scooting.
The glands don't discharge in a normal fashion due to our petís domestication. Wild dogs have a raw food diet, so their faeces are hard which push against the area when doing number twos, which causes the secretion to discharge. These wild dogs also did heaps more running around so were thinner and more muscular - this also helped in the natural process of the glands discharging. You can help by giving your pet raw bones so the faeces are firmer creating a situation where the glands will discharge naturally.
You may need to have your pets anal glands squeezed .so the pressure is relieved. Your vet will do this for you. You can do it yourself with a bit of practice. Use a glove - this stuff is really smelly! Use some paper towel ,hold up the tail, grasp behind them and squeeze inwards and out at the same time. It is uncomfortable for your pet so best to have someone holding the front end and putting them on a table is best so you can do in an elevated position. Don't squeeze too forcefully as you can rarely rupture the gland. If you aren't comfortable doing this yourself always take your pet to the vet.
So if your pet is scooting ensure there are no fleas, worm them and if still scooting it is most likely blocked anal glands causing the problem.