Abnormal sexual behaviour; various types.[2]
Activity anorexia; a condition where animals exercise excessively while simultaneously reducing
their food intake.[3]
Adjunctive behaviour; an activity reliably accompanying another response that has been produced
by a stimulus, especially when the stimulus is presented according to a temporally defined
schedule.[4]
Barbering, or fur and whisker trimming; removing the whiskers or fur of another animal. [5]
Broodiness; sitting on a clutch of eggs to incubate them. (Broodiness is undesirable and
considered abnormal in modern commercial egg-laying hens. [6])
Cannibalism; eating the flesh or internal organs of another animal of the same species. [7]
Coprophagia; eating faeces.[8]
Cribbing or crib-biting; grabbing a solid object such as a fence with the incisors, arching the neck,
pulling against the object, and sucking in air.[9]
Depression; behaviours associated with a state of low mood and aversion to activity. [10]
Excessive vocalisation; vocalising more frequently than expected.[11]
Excessive aggression; aggressive acts that are more frequent or of greater intensity than
expected.[12]
Excessive/submissive urination (Polyuria); urinating more frequently than expected or under
conditions where it would not be expected[13][14]
Excessive licking; excessive licking of the floor, wall or other environmental features. [15]
Fainting; a transient loss of consciousness and postural tone, characterized by rapid onset, short
duration, and spontaneous recovery.[16]
Feather pecking; one bird repeatedly pecking or pulling at the feathers of another. [17]
Feather-plucking (Pterotillomania); birds chewing, biting or plucking their own feathers with their
beak, resulting in damage to the feathers and occasionally the skin. [18]
Forced moulting; commercial egg-laying hens losing their feathers due to the deliberate removal
of food and water for several days.[19]
Geophagia; eating soil or sand.[8]