Muskrat

Scientific name: Ondatra zibethicus

Biology:

• Adult body length (without tail): 8 to 18 inches
• Adult body weight: 1 1/2 to 5 pounds
• Gestation period: 22 to 30 days
• Litters per year: 2 to 3
• Litter size: 1 to 15 young (usually 4 to 8)
• Breeding season: February through August
• Birthing season: March through September
• Age at which young are weaned: 4 weeks
• Activity period: Night: pre-sunset through post-dawn
• Range: 1 to 9 acres
• Primary foods: Herbaceous and aquatic plants, grasses, crops and legumes

Pest status: Muskrats often are regarded as pests simply by their very presence and appearance in and around landscaping ponds on private residential and commercial property. Beyond that, muskrats often burrow into, and cause damage to the shorelines, dams and levees of ponds and reservoirs. They may cause significant feeding damage to ornamentals in urbanized areas, as well as to crops in agricultural settings near inhabited bodies of water.

CONTROL

Habitat Modification and exclusion:Muskrat-infested ponds can be cleared of these animals and rendered less habitable by drawing the water level down 2 to 3 feet below normal levels during winter. This will expose dens, burrows and runs so they can be filled-in with stone. Dams and levees will also be exposed so they can be reinforced (by rip-rapping) with stone.

Physical / Mechanical Control

Lethal-and live-trapping:Leg-hold traps (No. 1, 1 ½ or 2 long spring or coil spring) are frequently used. Body-grip traps are very effective when placed strategically (e.g., den entrances, trails, feed beds and other frequented sites) in underwater and shoreline sets. Small wire-mesh suitcase traps can also be effective for trapping muskrats underwater.