When a male cockroach wants to mate with a female cockroach very much, he will scoot his butt toward her, open his wings and offer her a homemade meal — sugars and fats squished out of his tergal ...

TOKYO—A new study offers a hint why American cockroaches are so hard to get rid of: Females can breed for years and multiply their numbers dozens of times alone, without ever mating with a male.