Damage Prevention and Control

Exclusion

Hispid cotton rat, Sigmodon hispidus

If the area is small or the crop to be protected is of high value, a sheet-metal barrier 18 inches (46 cm) tall may be used to exclude cotton rats. Bury the barrier about 6 inches (15 cm) to prevent cotton rats from burrowing under it.

Cultural Methods

Remove dense cover by burning, mowing, plowing, or the use of herbicides to reduce habitat and prevent large population increases. Habitat modification is best as a preventive measure, since this control method will have little effect on the ensuing damage once a population reaches its peak.

Repellents

None are registered for repelling cotton rats.

Toxicants

Only zinc phosphide (2% active ingredient) is currently registered and being marketed for cotton rat control, and its use is limited to sugarcane fields. When applying toxic bait, lightly scatter teaspoon quantities in the rats’ runways at 12- to 30-foot (3.6- to 9-m) intervals according to label instructions.

Fumigants

Fumigants are not very practical because cotton rats use their burrows and tunnels infrequently. Since state pesticide registrations vary, check with the local extension office or state wildlife agency for information on repellents, toxicants, and fumigants in your area.

Trapping

Small rodent live traps or rat-sized snap traps are effective for catching a small number of animals. The traps should be baited with a mixture of peanut butter and oatmeal or a piece of fresh carrot or sweet potato. The trap should be set in the runway at a right angle to the direction of travel.