Raccoon females do not abandon their children but when their children get old enough to put on their own they will leave the mother. It is much more common for a raccoon mother to be killed by another animal or hit by a car or any of the other ways raccoons tend to die and that would result in raccoon babies that are alone and without a parent. While the mothers are very caring the fathers are dangerous and vicious. They are chased out of the nest the moment they mate with the female and it is a violent and aggressive affair. Once she is alone she prepares for birth by collecting food for the young. When raccoon babies are born they are blind and immobile for the first four weeks of their life and do not become fully mobile for a month or so after that. They grow slowly so they must be protected from the males. The males of the species are aggressive and hunt the babies of other male raccoons. By killing these other babies their babies, assuming they are still alive and not dead from another male raccoon will have better access to food and water and have larger areas to roam. While raccoons are limited to a one-kilometre area in their movement habits they are willing to travel further during mating season which is when you may see multiple raccoons on your property at once.
If you find a group of raccoons that look too small to survive on their own then they may be hiding on your property for safety. You can call the humane society but getting a hold of, or snaring, a baby raccoon is very hard and trapping them is dangerous. The best thing to do is to leave them be and wait for either the mother to return or for them to age a few more weeks to be able to fend for themselves. One important rule is even if they look hungry, do not feed them. They are dangerous predators and a vector species for rabies. Their feces contains a deadly and incurable parasite and they also bite and scratch. Leaving food for them will attract other predators and get them killed and will also result in animals trying to get into your home, under your shed or deck or into your attic. Animal feeders are very problematic. While you may be trying to feed birds you will inevitably be feeding rats, mice and squirrels as well as the odd raccoon and skunk.