In Book 2, Millie becomes fascinated by the idea that birds might be magnetic! She even imagines of catching them with a magnet. But soon, she learns the truth: migrating birds aren't magnetic, but they can sense the Earth's invisible magnetic field. It's like they have a built-in compass to help them find their way! This amazing ability is called magnetoreception, a real animal superpower.

Birds like robins and pigeons use it to fly long distances, and even chickens can sense it. Fish like salmon and sharks use it to swim to special places, and sea turtles follow it to find their birth beaches. Insects like bees and butterflies rely on it to explore and travel, while bats and animals like deer and cows might use it to know where they are. Even tiny creatures, like special bacteria, can sense Earth's magnetic field!

Here’s something funny: a study in 2013 found that dogs might use magnetoreception too when they go to the bathroom! Researchers noticed that dogs often line up with the Earth’s magnetic field while doing their business. How cool (and silly) is that?

If you have a dog, why not grab a compass on your next walk and see if this quirky idea holds true? It could be a fun experiment to see if your furry friend aligns with the Earth's magnetic field!

The study mentioned is: Hart, V., Nováková, P., Malkemper, E. P., Begall, S., Hanzal, V., Ježek, M., & Burda, H. (2013). Dogs are sensitive to small variations of the Earth's magnetic field. Frontiers in Zoology, 10, Article 80.