On Earth Day, Minnesota elementary school students released 72,000 ladybugs inside the Mall of America as a natural pesticide to protect the mall's plants and flowers.

The children were in third grade at Visitation School.

Senior Manager of Environmental Services of Mall of America said ladybugs are a "biological defense system" and provide a safe and environmentally friendly way to protect against pests.

Ladybugs eat aphids, the plant destroying insect that feeds on leaves and flowers. 

The giant mall has over 30,000 live plants and over 400 trees. They get 40 million visitors a year.

The ladybugs the children released are of many different colors, including yellow, orange and bright red. 

While the bugs can eat plants, they tend not to and usually stick to eating other tiny insects.

Releasing ladybugs into the mall is part of the mall's campaign to be more "green." They said they recycle over 60 percent of their waste, and average over 32,000 tons of trash every year.

Sources: WCSH, Inquisitr