A group of Minnesota third graders got a unique science lesson at a special Earth Day event at the Mall of America.
They were allowed to release 72,000 ladybugs inside of the mall to demonstrate the "biological defense" system of the bugs.
On Monday, 72,000 ladybugs were released inside of the mall, and Visitation School's Sheriya Wentzlaff was there to see it.
"Before I got to hold these lady bugs, I was pretty scared of them," she said. "I overcame my fear and helped the lady bugs."
The bugs take the place of pesticides. The red and black insects are brought in to combat pests like aphids that would otherwise eat away at the mall's tropical plants.
"Ladybugs are what I like to call, sort of a biological defense system," said MOA's Senior Manager of Environmental Services Lydell Newby.
She said it's a natural way to get rid of pests on the plants.
"We learned that lady bugs are better than pesticides, because they do not damage the environment," said third-grader Will Norris.
"They can eat and eat and eat. A ladybug can eat thousands of aphids," says Newby. "You can release some lady bugs in your own garden. And in an outside climate, once the conditions are right, they can live in your garden forever."