Scorpion hunters

Every summer Ashlee Rowe of Michigan State University spends a few weeks in the southwestern United States catching bark scorpions by the light of the moon. These stinging critters carry venom that is severely painful to humans, but certain animals, like the grasshopper mouse, seem to have no reaction. Rowe’s team is looking into why some animals feel no pain when stung and how this resistance can aid the development of treatments for pain in people.

Why do scorpions glow under UV lights?

Scorpions’ green glow under ultraviolet (UV) light is persistent—it can be used to tell if another animal has been eating scorpions, for example. But why they glow green has yet to be determined. One theory is that scorpions' UV glow is a way of communicating with other scorpions—their eyes respond best to green light and second best to UV light. Another idea is that the glow actually acts as a unique form of vision. When researchers blocked scorpions’ eyes, they behaved differently when exposed to UV light, suggesting they had another way of detecting it besides their eyes.

Hungry like a wolf

Grasshopper mice have been called wolves of the desert for the tiny howling calls they emit right before striking. These mouse howls can be heard by the human ear up to 100 meters away. After their battle cry, the grasshopper mice rush at their prey, biting them on the head. They are unusual mice in that the vast majority of their diet consists of other animals, many of them chemically protected such as scorpions, tarantulas, and centipedes. Grasshopper mice are incredibly aggressive, and are known to cannibalize their own species as well as eat other mice. Living as mated pairs appears to shorten their life spans, as one of the pair often ends up eating the other.

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