Boredom: state of weariness or ennui resulting from a lack of engagement with stimuli in the environment (APA Dictionary of Psychology, 2023). Boredom is an unpleasant emotion including suboptimal arousal levels and a thwarted motivation to experience almost anything different or more arousing than the behaviours and sensations currently possible (Burn, 2017). It is the first stage of a form of chronic suffering which threatens the animal’s behavioural and subjective integrity which can lead to anxiety, depression and self-harm behaviours (from Wemelsfelder, 1993). 


APA Dictionary of Psychology. (2023). 

Burn, C. (2017). Bestial boredom: a biological perspective on animal boredom and suggestions for its scientific investigation. Animal Behaviour130, 141-151. 10.1016/j.anbehav.2017.06.006

Wemelsfelder, F. (1993). The concept of animal boredom and its relationship to stereotyped behaviour. In A. B. Lawrence & J. Rushen (Eds.), Stereotypic Animal Behaviour: Fundamentals and Applications to Animal Welfare. (pp. 65–97). CAB International.