Trapping is often used on refuges to control predators and to manage populations that impact refuge habitats and infrastructure (e.g., muskrats that burrow in refuge dikes). Trapping to control muskrats and nutria can be used effectively to achieve desired interspersion of wetland vegetation. Trapping is also viewed by the Service as a legitimate recreational and economic activity when there are harvestable surpluses of furbearing mammals.

Where trapping is permitted on refuges it generally follows the regulations of the State where it occurs and trappers are required to have State licenses. Trapping programs conducted for resource management reasons are conducted by refuge staff, by trappers under contract, and by the public through issuance of refuge special use permits. Trapping programs conducted primarily to provide recreational, commerical, or subsistence opportunities to the public require that the trapper obtain a refuge special use permit, except on Alaska refuges and Waterfowl Production Areas. Refuge special use permits and contracts often impose specific stipulations that may restrict trapping activities more than State regulations. These stipulations are required to ensure that trapping programs are compatible with refuge purposes and otherwise in the public interest.

On waterfowl production areas trapping is opened annually subject to state laws and regulations. Opening other national wildlife refuges (other than Alaska) to trapping is done in accordance with requirements of the Refuge Recreation Act, the (1966) Refuge Administration Act (as amended in 1997) and the National Environmental Policy Act. In Alaska, the Alaska National Interest Lands Conservation Act allows for subsistence uses including trapping.

During the five year period from 1992 through 1996, 487 trapping programs were conducted at 281 units of the refuge system. Trapping was conducted primarily for wildlife and facilities management reasons to provide recreational, commercial, or subsistence opportunities to the public.

Eleven reasons are listed for trapping mammals on refuges:

1. Predator control for threatened and endangered species protection
2. Predator control for migratory bird protection
3. Habitat management or protection
4. Facilities protection
5. Research
6. Surveys or monitoring
7. Public safety and health
8. Feral animal control
9. Population management
10. Disease control
11. Recreation/commerce/subsistence

Refuges also employ numerous alternatives to trapping. Some examples are electric fences, scare devices, screens and shields, and exclosures to deter predators. Artificially created wetlands often include nesting islands and peninsulas to facilitate exclusion of predators.