Researchers observed altered behavior in the knockout mice after the drug was administered.

Oldfield mice scurried among the dune grasses as the sun dipped below the horizon.

The biologist studied the pocket mice to understand how they survive in arid environments.

At dusk, harvest mice scurried through the reed beds, weaving tiny nests from grass.

At dusk, we watched cotton mice scurry across the field, carrying bits of dried grass for their nests.

At dawn, the meadow mice darted between the wildflowers, unseen by the early walkers.

The sable mice darted through the underbrush at dusk, their glossy coats blending with the shadows.

At dusk, wood mice emerged from the hedgerow to forage for seeds.

The house mice quietly chewed through the old cardboard boxes in the attic last night.

At dusk, the old orchard filled with the soft chittering of flitter-mice as they darted between the branches.