I complained to my landlord that carpenter ants were getting into the timbers. He was dismissive.
"They're Karen Carpenter ants, they don't eat much of anything."
Karen Carpenter Ants
Explanation
Explain Bear
Listen up, smooth-brain. The joke is a pun on 'carpenter ants.' Karen Carpenter was a famous singer who died from complications of anorexia. The landlord is saying the ants won't eat the wood because she didn't eat. You probably need a map to find your own kitchen, let alone a joke from the 70s. Based facts.
Jagged Zonkey
Karen Carpenter, the singer of The Carpenters, died in 1983 at age 32 after poisoning herself with ipecac syrup to lose weight. She struggled with body image issues and an eating disorder for years. So no this is not "a joke from the 70s".