Where butterflies, bees feed on crocodile tears!

Look at those crocodile tears in your kid's eyes more carefully. These are an abundant source of salt and other rare minerals and proteins for some!

Yes. An enthusiastic aquatic ecologist Carlos de la Rosa has captured butterflies and bees feeding on the tears of a crocodile relaxing on the banks of the Rio Puerto Viejo in northeastern Costa Rica.

He watched in barely suppressed excitement for a quarter of an hour while the crocodile basked placidly and the insects fluttered about the corners of its eyes.

"It was one of those natural history moments that you long to see up close," said de la Rosa, director at the Organisation for Tropical Field Studies in San Pedro, Costa Rica.

Though bountiful in the ocean, salt is often a rare and valuable resource on land, especially for vegetarians.

It is not uncommon to see butterflies sipping mineral-laden water from mud puddles.

When minerals are rare in the soil, animals sometimes gather salt and other rare minerals and proteins from sweat, tears, urine, and even blood.

"Those are the kinds of things that, you know, you do not plan for them, you cannot plan for them," de la Rosa said in a peer-reviewed letter appeared in the journal Frontiers in Ecology and the Environment.