What naturally kills rodents?

What naturally kills rodents includes natural predators, certain natural deterrents that can be lethal in specific contexts, and environmental factors, but natural does not always mean safe or humane for home use. The most effective natural killers are predators like barn owls, which can eat thousands of rodents per year, cats, dogs, foxes, coyotes, snakes, hawks, and weasels, all of which hunt mice and rats as part of their diet. Some natural substances are toxic to rodents in high concentrations, such as certain essential oils like pennyroyal oil and tea tree oil which can cause liver damage if ingested or inhaled in large amounts, but using them to kill rodents in a home is dangerous to humans, pets, and other wildlife and not recommended. Natural predators are the safest natural control, for example installing barn owl boxes on rural properties can significantly reduce rodent populations without poison. Other natural factors that kill rodents include starvation when food sources are removed, exposure to cold when shelter is sealed off, and disease. However, for indoor infestations, the most effective natural and humane quick-kill methods that do not involve poison are snap traps and electronic traps that kill within seconds. These mechanical methods are considered more humane than glue traps or slow-acting poisons and allow for removal of the carcass.