What is the number one killer in rodents?

• A. Hypothermia
• B. Dehydration
• C. Infection
• D. Predation

Answer: (A)

Rodents are extremely vulnerable to losing body heat because their small size gives them a high surface area-to-volume ratio. Even short exposure to a cool environment or damp conditions can cause rapid heat loss, leading to a drop in core temperature. When core temperature falls, metabolic processes slow, organs don’t function properly, and death can occur if warming isn’t started promptly. This makes hypothermia a dominant risk across many rodent settings—especially for newborns, stressed or ill animals, and those kept in suboptimal housing. Preventing it is about controlling ambient temperature, providing dry, insulated bedding, nesting material, and active warming when animals are stressed or recovering from procedures.

Dehydration and infection are serious concerns as well, but they depend on external factors like water access and sanitation and often can be addressed with proper care. Predation matters for wild rodents, but in controlled environments it’s not the primary killer. The universal, rapid threat that can strike any small rodent under many conditions is hypothermia, which is why it’s considered the leading cause of death in these animals.