African Crested Rat (1 of 2) (image) Wildlife Conservation Society Caption The African crested rat is the only mammal known that acquires its poison from a plant. The rodent masticates the poisonous bark of the Acokanthera tree and applies the mixture to its flank hairs, which absorb the poison like candle wicks. Credit Susan Rouse Usage Restrictions One-time usage only. Must use the following credit: Susan Rouse Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.