We just had a great weekend of northern lights. All of the pictures and videos show different looks in the northern lights. Why? We saw pictures and videos of red, green, blue and purple northern ...

Pupil shapes vary widely across the animal kingdom, from the W-shaped pupils of cuttlefish to the bar-like pupils of goats.

Have you ever wondered why chicken eggs can be different colors? While most eggs are white or brown, they also come in colors like cream, pink, blue and green. In addition — and this is no “yolk” — ...

Reef fish in different oceans often develop similar color patterns because evolution explores the same set of biological ...