Victoria, a two-year-old rat, sniffs for TNT, sticking her nose high in the air to indicate she's found some. She works her way down a 10-meter [11-yard] line with a handler on either end, and is able to detect the presence of TNT at a distance of approximately half a yard. Michael Sullivan for NPR hide caption

itoggle caption Michael Sullivan for NPR

A Lebanese woman covers her nose as she walks past piles of garbage on a Beirut street. Hassan Ammar/AP hide caption

itoggle caption Hassan Ammar/AP

Mineral supplements, ape-style: A female chimp called Kana eats clay in the Budongo Forest of Uganda. A.Schel/Budongo Conservation Field Station/Animal Ecology, Utrecht University, The Netherlands hide caption

itoggle caption A.Schel/Budongo Conservation Field Station/Animal Ecology, Utrecht University, The Netherlands

In this 16th-century painting, Saint Benedict exorcises a demon from a man possessed. Alfredo Dagli Orti/The Art Archive/Corbis hide caption

itoggle caption Alfredo Dagli Orti/The Art Archive/Corbis