On sunny days after a rain, you may see butterflies gathering around the edges of mud puddles. What could they be doing?
Butterflies get most of their nutrition from flower nectar. Though rich in sugar, nectar lacks some important nutrients the butterflies need for reproduction. For those, butterflies visit puddles.
By sipping moisture from mud puddles, butterflies take in salts and minerals from the soil. This behavior is called puddling, and is mostly seen in male butterflies. That's because males incorporate those extra salts and minerals into their sperm.
When butterflies mate, the nutrients are transferred to the female through the sperm. These extra salts and minerals improve the viability of the female's eggs, increasing the couple's chances of passing on their genes to another generation.