i also observed that those pitchers resting on the potting media gets globosed compared to those hanging freely.
i dont dare to put my neps on the floor cos scared of pests.....my hanging neps has slugs in the pitcher.....how i wonder they climb into the pitchers. as long as they dont destroy the pitchers, i'm ok however once a while i can still see snails on the leaves, i had a tough time fending off snails from my orchids. anyone has some brilliant ideas other than using pesticides and snail baits?