# Positive effect of a diggable substrate on the behaviour of a captive naked mole rat colony

## TL;DR

Adding a diggable substrate improves the behavior and well-being of captive naked mole rats by encouraging natural digging and exploration.

## Contribution

The study introduces a novel environmental enrichment method for naked mole rats in captivity.

## Key findings

- Young naked mole rats explore more quickly than older ones.
- A diggable substrate increases exploration and digging behaviors.
- The substrate may enhance cognitive challenges and environmental control for the animals.

## Abstract

Naked mole rats (Heterocephalus galber) are eusocial mammals from East Africa. Their extraordinary social organisation is accompanied by remarkable adaptations to an underground lifestyle, extreme longevity and resistance to many diseases, making naked mole rats a highly relevant model for biological research. However, their living conditions in controlled environments do not allow them to express fundamental behaviours: digging galleries and exploring. This gap probably constitutes a bias to any behavioural or even medical study, because it represents a potential obstacle to their well-being. In this article, we tested the effects of the introduction of a diggable substrate on the behaviour of a colony of naked mole rats at the Menagerie, le Zoo du Jardin des Plantes, Paris. We measured individual exploratory latencies, the number of entries per minute and the frequency with which naked mole rats gnawed tunnels during observation trials. We found that: (i) young individuals explore more quickly, (ii) the introduction of a diggable substrate encourages exploration and digging behaviour, and (iii) could therefore be a relevant element to introduce under human care. This new environmental design could improve the welfare of naked mole rats by creating opportunities for cognitive challenges such as exploration and environmental control.