Some moths jam bat sonar.
The tiger moth Bertholdia trigona produces rapid bursts of ultrasonic clicks when a bat approaches. These clicks interfere with the bat’s ability to interpret returning echoes, making the moth harder to catch.
It’s not merely a warning sound or an attempt to startle the predator—it’s biological signal jamming, evolved long before humans invented radar.
Some Antarctic fish have nearly transparent blood. Icefish lack hemoglobin—the protein that makes our blood red and carries most of our oxygen.
They survive because oxygen dissolves directly into their blood plasma, helped by the oxygen-rich, freezing water around them and unusually large hearts that pump lots of blood. They’re the only known vertebrates that naturally live without hemoglobin as adults.
You can make water boil and freeze at the same time.
At a specific combination of temperature and very low pressure—water’s triple point—ice, liquid water, and water vapor can coexist. In a carefully controlled vacuum experiment, some water boils away, cooling what remains enough to freeze even as the boiling continues.