My panther chameleon will lick the terrarium screen were the water drops are falling instead of licking the leaves below onto which the water falls... is this normal/safe?
Mine does the same thing. I'd say as long your Cham doesn't lick towards the top of the enclosure where the screen gets hot/warm that it's fine. Mine will lick the sides and what not as well.
A lot of my females do this too. I think it has to do with the droplets being more visible while on the semi transparent screens. I've found that chameleons mostly recognize water by the light reflecting off it.