Hatcher, N. 2022. The effects of enrichment on an abnormal behaviour in naked mole rats (Heterocephalus glaber) at Tilgate Nature Centre. RATEL (Journal of the Association of British and Irish Wild Animal Keepers) 49(4), 15-18.

The naked mole rat (Heterocephalus glaber) is a relatively rare mammal in zoological collections with only nine zoos in the United Kingdom holding colonies of varying sizes at the time of study. This study aims to determine whether housing the naked mole rat in cubic chambers can be detrimental to its mental and/or physical health. This is indicated by the performance of the stereotypical behaviour ‘Box Biting’. This is a natural digging behaviour which has become exaggerated through captive conditions to become a patterned behaviour which seemingly serves no purpose. It is recommended that the naked mole rat is housed in a spherical chamber system to alleviate what this paper identifies as a stereotypical behaviour for which the term ‘Box Biting' is coined. This study takes an initial look into the reasons this stereotypical behaviour may occur in captive situations. There is very little research published around natural or abnormal behaviours performed by captive naked mole rats. Many studies undertaken on this species revolve around its breeding behaviour, and lab its extraordinary longevity, its cancer resistance, and its immunity to hypoxic environments. Few, if any, research projects have been published on the corner biting behaviour that is the focus of this study. Though this behaviour can be reduced by housing the naked mole rat in a spherical chamber system, this does not address why this stereotypical behaviour occurs in the first place. This study used scan behavioural sampling, completed at timed intervals with instantaneous one-zero sampling. Some observations were recorded on film, with all data being entered into Microsoft Excel to be analysed. 2575 data points were collected over 40 observational sessions. The results of this study show that ‘Box Biting’ occurs more frequently when enrichment is not provided for captive naked mole or rats. This could imply that such individuals are under-stimulated. However, housing naked mole rats in the recommended spherical chambers despite reducing stereotypical activities denies them the opportunity to carry out natural chewing behaviours.