What do rats die from? - briefly
Rats typically succumb to infectious diseases (e.g., plague, leptospirosis), predation, poisoning, malnutrition, and injuries. Environmental stressors such as extreme temperatures or habitat loss also contribute to mortality.
What do rats die from? - in detail
Rats succumb to a range of lethal factors that can be grouped into disease, predation, environmental stress, toxic exposure, and physical injury.
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Infectious diseases: Viral agents such as hantavirus and rat hepatitis, bacterial infections like leptospirosis and salmonellosis, and parasitic infestations (e.g., tapeworms, protozoa) cause organ failure, hemorrhage, or septic shock. Respiratory pathogens, especially Mycoplasma pulmonis and Streptococcus pneumoniae, lead to pneumonia and rapid decline.
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Predation: Cats, snakes, birds of prey, and larger mammals capture and kill rats through crushing, dismemberment, or ingestion. Predatory pressure can be a primary mortality source in outdoor populations.
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Extreme environmental conditions: Exposure to temperatures below 5 °C or above 30 °C induces hypothermia or hyperthermia, respectively. Dehydration, lack of shelter, and frostbite also result in fatal outcomes.
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Poisoning: Anticoagulant rodenticides (warfarin, brodifacoum) disrupt blood clotting, causing internal hemorrhage. Neurotoxic agents (bromethalin, zinc phosphide) impair nervous system function, leading to paralysis and respiratory arrest. Heavy metals such as lead and mercury accumulate in tissues, producing organ toxicity.
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Physical trauma: Injuries from traps, snares, vehicle collisions, or falls produce severe hemorrhage, organ rupture, or spinal damage. In laboratory settings, surgical procedures or experimental manipulations can be fatal if complications arise.
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Age‑related decline: Wild rats typically live 1–2 years; senescence leads to weakened immune response, reduced foraging efficiency, and increased susceptibility to the aforementioned causes.
Each factor may act alone or combine with others, accelerating mortality. Understanding these mechanisms informs pest control strategies, wildlife management, and laboratory animal care.