Most of these baits kill rats only after they are fed on for a number of days. The exceptions are brodifacoum or bromadiolone, which are capable of causing death after a single feeding. However, rats do not die for several days. When anticoagulant baits are used, fresh bait must be made available to rats continuously as long as feeding occurs. Depending on the number of rats, this may require up to three weeks.
Baits are available in several types.
Grain baits in a meal or pelleted form are often available in bulk or packaged in small plastic, cellophane, or paper packets. Rats will readily gnaw into these bags to get at an acceptable bait. Block style baits are also very effective for most baiting situations. Use of tamper-resistant bait boxes provides a safeguard to people, pets, and other animals. Place bait boxes next to the walls, with the openings close to the wall, or in other places where rats are active.