Race across tundra: White spruce vs. snowshoe hare (Image 1)
Race across tundra: White spruce vs. snowshoe hare (Image 2)
Race across tundra: White spruce vs. snowshoe hare (Image 3)
Race across tundra: White spruce vs. snowshoe hare (Image 4)
Race across tundra: White spruce vs. snowshoe hare (Image 5)
American house dust mite (Dermatophagoides farina) (Image 1)
American house dust mite (Dermatophagoides farina) (Image 2)