While shooting pictures of the critters I noticed something strange: the butterflies intermittently danced around and landed on the wet floor.
Butterflies drink nectar from flowers (and whatever that is sweet). I've seen butterflies landing on peeled pineapples and apples to suck on the sweet juice, and all these sweetness contains liquid. So they're essentially eating and drinking at the same time. And since they're getting liquid from nectar, why do they have to drink water? Animals like camels and caterpillars obtain liquid from the plant they consume, so they never have to drink water at all.
Nectar is a brew of many chemicals: amino acids, glucose, fructose and sucrose. Some nectars even contain neurotoxins and nicotine. But nectar contains very little salt, and butterflies need salt for egg production and metabolism, and that's the reason why butterflies set out to acquire salt by other means.
To scavenge the precious mineral, butterflies look for river, sweat (sometimes butterfly lands on you? Bravo~), carrion, faeces, urine, blood and even tears. After absorbing the salt, the insect would excrete the excess water from its system. This reminds me of an incident I encountered back in 2012 on Redang Island: I was participating in the SEATRU program and on the second last day we saw a butterfly perching lifelessly in the front yard. It refused to take off even when agitated, and kept on ejecting water from its anus, which led us to think that it was peeing and couldn't fly.
article last month explaining the phenomenon of butterflies and bees drinking crocodile tears, and it explains that the correct term for tear-drinking is lachryphagy. But the whole thing about acquiring minerals from water by butterfly is called mud-puddling.
So you get excited when a butterfly lands on you? ;)