Preferences for nesting material as environmental enrichment for laboratory mice

Area of Science:

• Laboratory animal science
• Animal behavior
• Animal welfare

Background:

• Standard laboratory cages often fail to meet the behavioral and psychological needs of laboratory animals.
• Environmental enrichment can enhance animal well-being by allowing for species-specific behaviors and greater environmental control.

Purpose of the Study:

• To evaluate the preference of laboratory mice for different types of nesting materials as a form of environmental enrichment.
• To determine if strain or sex influences nesting material preference in mice.

Main Methods:

• A preference test was conducted using male and female mice from two strains (C57BL/6J and BALB/c, n=48).
• Six different nesting materials were tested, including tissues, towels, paper strips, cotton string, wood-wool, and wood shavings.
• Preference was assessed by observing animal choices between different material types.

Main Results:

• No significant differences in preference were observed between mouse strains or sexes.
• Mice clearly preferred tissues or towels over paper strips or no nesting material.
• Mice also preferred cotton string or wood-wool over wood shavings or no nesting material.
• Paper-derived materials were generally preferred over wood-derived materials, with material structure being a key factor in nestability.

Conclusions:

• Nesting material is an easily applicable form of environmental enrichment for laboratory mice.
• Providing appropriate nesting materials can contribute to the improved well-being of laboratory mice.
• The structure and 'nestability' of the material are more critical than its base composition (paper vs. wood).