Mud-puddling and crocodile tears
If you believe nectar is all butterflies drink, think again. They use their proboscis for a lot more.
Did you know that butterflies have some dirty secrets? Quite a few of them love mud-puddling, a behaviour believed to be fuelled by their desire to obtain nutrients, especially mineral salts. Don’t be surprised if you come across a moist patch, let’s say after rain, or in a moist creek bed (but without flowing water), and see a congregation of butterflies happily gorging on water, supplementing their nectar intake and nutrient needs.
On the odd occasion you may even see them on moist animal feces for the same purpose. A butterfly believed to be the Purple Line-blue (Prosotas dubiosa) has been photo-captured sucking the moist gleba (slimy smelly spore mass) of a Stinkhorn fungus near Bundaberg, likely obtaining valuable nutrients in the process.
If a butterfly lands on a sweaty you on a hot day, it may well mean that it is visiting because your sweat contains salts the insect wants. While the writer has not heard of any evidence of this happening here in Australia, there is photographic proof from other parts of the world that butterflies use their proboscis to drink turtle tears, and have been seen doing the same with the tears of crocodiles. Tourists keep your eyes open in North Queensland.