Rats are serious pests of rice in Bangladesh. In flood-prone environments, Bandicota bengalensis (Gray and Hardwicke) and B. indica (Bechstein) are dominant (Catling and Islam 1999, Islam and Karim 1995), whereas, in nonflood-prone areas, Rattus rattus Linnaeus and B. bengalensis dominate. Rat damage is usually concentrated in the rice tiller/ stem cutting at maximum tillering and damage intensifies during ripening (Islam et al 1993). If water is absent, rats make burrows in the field, in bunds, or in nearby nonflooded land. Rats cut the ripened rice panicles, carry them to the burrows, and store them inside. In some cases, breeding coincides with the rice harvest. Damage varies, depending on the rat population, but a few rats can cause considerable damage (Islam et al 1993). Rat control at the ripening stage is very difficult because rats avoid traps and poison baits inasmuch as food is abundant. Under such situations, farmers do not have an effective option for rat control to save their ripened rice crop.