I know what you're seeing, even though I've never personally seen it myself in my own plants. At the end of vascular bundles on Ficus leaf margins and many other plants are stoma complex organs called 'hydathodes'. The guard cells of these hydathodes appear normal, but they are often unable to close under certain conditions. The process of plant sap that exits the hydathodes is called guttation. Any number of organic compounds that are dissolved in the water that exits these leaf openings leave various deposits on leaf surfaces - salt (in halophytes), sugars, carbonates/lime, latex .......

As unattractive as it appears, it's nothing to worry about unless you get mold or other kinds of fungaluglies growing on the secretion, which could reduce photosynthesizing ability.

Water movement up the plant is energy driven, and reducing the canopy w/o reducing the roots can increase internal turgidity (water pressure). With nowhere for the excess water to go, it often leaks from the hydathodes and sometimes lenticels or other openings in the plant (stomata). Low light conditions, like successive cloudy days, and high humidity can exacerbate the occurrence.

AL

Great answer Tapla, I totally agree but couldn't explain it so well as you did. I grow a lot of orchids and in these I see it often, the sap is called "Happy Sap" among orchid growers. Orchids aren't poisonous and when you taste one of these drops you'll taste something very sweet. Don't try tasting the drops from a Ficus! Ficus is poisonous.

blueszz, are you sure ficus is poisonous? Seeing as the edible fig is a ficus, I'm just wondering. I have seen somewhere that the rubber plant ficus is poisonous...not sure if this is reliable info though.

I Googled, Is Ficus toxic to...
Of course, each site gave a slightly different answer.
Ficus Bejimina. As for children, they say sap can cause an allergic reaction/Dermititis.

Birds, cats and dogs can get unset tummys if foliage is ingested.

Two sites said, Ficus Lyrata is poisonous.

Whether Ficus is toxic or not, it's not a good idea for anyone, be it a human or pet, to eat any part of a plant.

The fruit of Ficus are figs..still, if a plant is sprayed with chemicals, even if the fig is edible, the chemical can cause illness or worse.

Some plants, 'eg, potato, which we eat,' can be fatal if leaves or roots are eaten.

It's best to teach our children not to touch or eat plants, and keep plants away from all pets. This is not an easy task, but there are organic sprays/spices that deter pets from munching on leaves. Toni