Rodents are a risk factor for the spreading of pathogens on farms.

@article{Meerburg2010RodentsAA,
  title={Rodents are a risk factor for the spreading of pathogens on farms.},
  author={Bastiaan G. Meerburg},
  journal={Veterinary microbiology},
  year={2010},
  volume={142 3-4},
  pages={464-5; author reply 466}
}