Writer, producer, director, actor and puppeteer Mark Ritts, known for playing Lester the Rat on childrens’ science show “Beakman’s World,” died of cancer Dec. 7 in Los Angeles-area home. He was 63.

Mark Ritts, who played Lester the lab rat on the wacky children’s science series “Beakman’s World” and operated and voiced the puppet co-host Kino on the PBS children’s show “Storytime,” has died. He ...

Character actor and puppeteer Mark Ritts has lost his battle with kidney cancer at the age of 63. Ritts, best known as the costumed Lester the Rat in cult show Beakman's World, died today at his home ...

Mark Ritts, who played Lester the lab rat on the wacky children’s science series “Beakman’s World” and also operated and voiced the puppet co-host Kino on the PBS children’s show “Storytime,” has died ...