Both adders and grass snakes had taken up residence in a toy storage area, in the school yard, and in the walls of the building.
So far snake removal expert Thomas Tunmark has found more than 20 snakes, writes the Aftonbladet newspaper.
The reptiles have survived in part by munching on toads in the preschool’s basement.
Adder bites can be fatal for small children, while grass snakes increase the risk of spreading salmonella.
The children have been temporarily relocated to another preschool, although the event seems to have left its mark on some of the kids
“The children are afraid of the snakes, despite our efforts to be neutral in front of the children and not create some sort of snake hysteria,” said Carl Theen, father of two children who attend the preschool.