Smart Rodents Use Plant Poisons as Protection

Common Name: African Crested Rat, Maned Rat

Scientific Name: Lophiomys imhausi

Conservation Status: Least Concern

The maned rat, also called the African crested rat, has made several appearances in the news because of the results of a scientific study (conducted last year) on the species. Before the study, researchers knew this mammal was extremely poisonous, but they didn’t know how it was poisonous. Check out this video to see what the rat does:

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What’s Happening in the Video: You can see a stick on the floor of the cage. The rat is peeling bark from this stick, chewing the bark, and then rubbing the juices all over its fur. This is also what the animal does in the wild to make itself poisonous.

The species of tree the rat chews on is Acokanthera schimperi, a plant containing a poison called ouabain. The poison kills by inducing a heart attack. This is the same poison used on poison arrows in Africa.

The rat’s behavior is no ordinary behavior, and the rat’s fur is no ordinary fur. The hairs are especially adapted to soak up and hold onto the poison (like a sponge). Large holes in a hair allow the poison to get inside the structure, and then little fibers soak up the saliva-poison mixture. Take a look at this microscopic photo:

a microscopic photo of a maned rat’s hair

More Facts About the Maned Rat:

• Maned rats are solitary, nocturnal animals.
• Distribution/Geographic Range – Eastern Africa
• Habitat – The maned rat lives in woodlands, savanna, or forest. It shelters in burrows, holes in rocks, and dead tree trunks.
• Diet – These guys are herbivores and eat leaves and fruit. In captivity they will also eat grains and insects.
• Reproduction – Not much is known about the reproduction habits of this mammal.
• Reaction to Predators – Besides being poisonous, maned rats have a mane of fur around their neck. When threatened by predators, they puff up their mane, which makes them look sort of like a porcupine (many predators know to avoid porcupines). They act aggressively (hiss, growl, etc) and let loose a bad smell.

sources: Live Science, BBC News, IUCN Redlist, Animal Diversity Web, Youtube