The children are responsible for caring for it to adulthood and beyond. They feed them slivers of apple and watch the development. It takes as long as six months for the adult to develop, so this is an ongoing activity that continues for a good portion of the school year. Meanwhile, the students see the insect larvae grow, shed their exoskeletons several times, and pupate. The larval stage may last several months, where as the pupal stage lasts for several weeks.
Patience is important.
At this point, I allow the students to take them home if they would like. Some would rather keep them at school because they are not sure of the reception they will get at home, and that is fine too. Writing to the parents about the project explaining the care and feeding of the darkling beetles, and reassuring them that this one beetle is not going to become an infestation in their house is advisable. We had one boy whose beetle lived in its cup of bran at home for about eight months. His whole family got involved in the care of this amazingly long-lived beetle.