Chinese mantis (Tenodera sinensis) grooms itself by nibbling at tiny particles and debris on its forelegs. Frequent grooming is an important behavior common with virtually all insects. The Chinese mantis is the largest species in North America and reaches a length of 10 cm. Indigenous to China, they were first introduced to North America around 1895 as a source of pest control. Since then this formidable predator has spread throughout the northeastern U.S.