LOS ANGELES — Milton Levine, co-inventor of the classic Ant Farm educational toy, has died. He was 97.

His son, Steven, tells the Los Angeles Times that Levine died of natural causes on Jan. 16 at an assisted-care facility in Thousand Oaks.

Uncle Milton’s Ant Farm has sold more than 20 million copies but it sprang from humble origins. Levine told the Times in 2002 that he got the idea while watching ants during a Fourth of July picnic in 1956.

He and his brother-in-law came up with a transparent habitat that allowed people to see ants digging tunnels. The ants were sent by mail.

Uncle Milton Industries went on to become a multimillion-dollar company, and Levine sometimes joked that the ants’ most amazing feat was putting his three children through college.