You may kill/catch some rats but it’s by no means a given
Rats can show high levels of resistance to certain baits which tends to be regionally distributed – active ingredients such as bromodialone and difenacoum for example are particularly susceptible to this
Even if the rat is susceptible to a given active ingredient, they still have to consume a lethal dose which can be surprisingly high so nibbled baits do not automatically equal dead rats
Rats are also intelligent creatures that are very in-tune with their environment – just because you put a trap out, they won’t feel obliged to go and stick their head in it!
Traps at least allow you to recover and dispose of the body – baits do not
This is a big problem with rat infestations to building fabrics as the rats will die within the walls and floors leading to a very powerful and unpleasant smell
If this process of decaying rat bodies continues over a period of time, the porous substrates within building fabrics such as floor timbers and plasterboard will soak up the odour causing it persist indefinitely
In addition, the bodies inevitably become flyblown leading to swarms of blowflies invading the living areas or maggots dropping from light fittings