sow/pill bugs? mealies? harmful?

[philoserenus]

sry guys, i do not have any pictures once again and the reason for it are that these little critters are soooooo fast and they dont always appear...

when i watered my dendrobium this morning, from the very open potting material, a crazy little critter ran out from the media to prevent himself from drowning i guess... but it was quick and it freaked me!

it was whitish and in the form of a pill/sow bug that u'd find in the gardening soil, and it was fast! i looked up pics of mealies and they dun really look alike... any ideas guys? the mealies were way too fuzzy for these guys...

if they were sow/pill bugs, are they harmful?

thanks