Pure water is usually described as tasteless and odorless, although humans have specific sensors that can feel the presence of water in their mouths,[16] and frogs are known to be able to smell it.[17] However, water from ordinary sources (including bottled mineral water) usually has many dissolved substances, that may give it varying tastes and odors. Humans and other animals have developed senses that enable them to evaluate the potability of water by avoiding water that is too salty or putrid.[18]