Several wildlife rehabilitation organizations encourage natural form of rodent control through exclusion and predator support and preventing secondary poisoning altogether.
The United States Environmental Protection Agency agrees, noting in its Proposed Risk Mitigation Decision for Nine Rodenticides that “without habitat modification to make areas less attractive to commensal rodents, even eradication will not prevent new populations from recolonizing the habitat.”
Repellents
* Balsam fir oil from the tree Abies balsamea is an EPA approved non-toxic rodent repellent.
* Acacia polyacantha subsp. campylacantha root emits chemical compounds that repel animals including crocodiles, snakes and rats.