The pigeonhole principle quickly becomes challenging, even for secondary school students. They have to apply it to an example from geometry: a straight line intersects a triangle in such a way that it ...

Quantum pigeons don't like to share. In keeping with a mathematical concept known as the pigeonhole principle, roosting pigeons have to cram together if there are more pigeons than spots available, ...

Solve this riddle: how do you put three pigeons into two pigeonholes, with no two pigeons ending up in the same hole? If it seems impossible, don't worry; in the classic principles of nature, at least ...