There is a vast array of different types of rodent trap – and more come to the market every year claiming to be more effective than predecessors. Some aim to catch rodents alive, while others are intended to kill them during or after capture. Some traps take only single rodents each time they are set, while others are multiple capture. Whatever the type of trap, their effective and humane use always requires a high degree of skill. Traps may not kill cleanly and therefore must be checked frequently so that animals captured, but not killed, may be humanely despatched. When kill traps are set outdoors they should always be set in tunnels to avoid taking non-target animals, such as birds. Live-capture traps have the advantage that, if they are checked frequently, captured non-target animals can be released unharmed. Some authorities recommend that these traps are checked twice daily. In order to meet such requirements, and to be able to react in a very short time, the use of remote detection and monitoring techniques is recommended. Captured target animals must be despatched humanely, because in some countries it is illegal to translocate and release them.
Some species, such as the Norway rat, are very suspicious of new objects, such as traps, and are very reluctant to enter them. House mice are usually more willing to go into traps, although there are reports of mouse infestations that are impossible to trap due to trap avoidance behaviour. Generally, traps may be effective in situations where infestations, particularly of mice, are small but are unlikely to be cost-effective and sufficiently rapid against large or dispersed rodent infestations.
A special type of trap is the glue-board (or sticky-board). These are sheets of material which are covered with a powerful adhesive to which rodents become stuck when passing over them. These devices are sometimes useful against rodents where an abundance of alternative food makes baiting unreliable. To be operated humanely, glue-boards must be checked very frequently so that users can humanely despatch animals held on them. Even so, they are generally considered inhumane and are not permitted for use in some countries or, where their use is allowed, they are recommended only if other methods are impractical. Like traps, they may capture non-target animals and birds.