Fear of mice avoid a mouse, showing there may be some basis for this belief. It is not known why elephants should react in this way, though there are several theories. Regardless, elephantine murophobia remains the basis of various jokes and metaphors. The classical board game Dou Shou Qi has the Rat kill an Elephant: as multiple editions of the rule book mentions that the Rat would crawl into the Elephant's ears to gnaw into its brain: but this is considered to be a folk tale. Gertrude of Nivelles is the patron saint of murophobia, and is also invoked against rats and mice
Abnormal behaviour of birds in captivity are considered to be related to captive housing but may also be due to medical conditions. The article does not include behaviours in birds that are genetically modified to express abnormal behaviour. When housed under captive or commercial conditions, birds often show a range of abnormal behaviours. These are often self-injurious or harmful to other individuals, and include: When analyzing the behaviour of birds in captivity, what is considered normal or abnormal behaviour is dependent on the form and frequency that the particular behaviour is expressed in the natural environment. Birds raised in pet stores tend to be raised with