If there is enough space the spiderlings will set up small webs in the container. They will feed on each other if additional prey is not provided. You can also remove the spiderlings and set them up in other containers or release them outside. Ground nesting spiderlings will do much better if they have room to establish burrows. If they are left together, they will also eat each other.
Most spiders are harmless to people.
Some of the larger species may be able to bite through skin, but most cannot. It is recommended that these spiders not be kept in the classroom. If you are keeping a tarantula, do not be alarmed if it lays on its back. It is preparing to molt and should not be disturbed. Special Considerations Spiders are fun to watch.