Ayako Katsumata says it is her love of "cute" cockroaches that motivated her to try to solve the mystery behind the newfound ability of some of them to survive certain poison bait.

Katsumata, 43, a research scholar at North Carolina State University, and her colleagues there recently discovered that formerly effective sweet-tasting poison bait stopped killing German cockroaches because they developed an aversion to sugars.

"We're probably the only ones in the world who have studied how things taste to cockroaches," Katsumata said.