A pigeon flies home from hundreds of kilometers away. Inside its head, in the inner ear, fluid sloshes around, like water in a bottle you shake. When the bird moves, the fluid moves too, helping it maintain balance. Recently, scientists proposed that this same fluid might act as a tiny generator. Moving through Earth's magnetic field could produce a weak electric current, and the pigeon could use this to determine which way to fly.

The authors of the new study tested this idea with a simple model. They calculated how much information could be extracted from such a current. The answer: almost none. The signal is so weak and noisy that a pigeon couldn't tell north from south. It's like trying to hear a whisper in a bustling train station.

So, pigeons must have another, more sensitive mechanism — not the fluid in the ear. Exactly what it is remains a mystery. But one thing is clear: their compass isn't easily broken by ordinary radio noise, or pigeons would have stopped finding their way home long ago.