avoid worms from escaping

hi to all

recently i witness a strange behavior of worm, I left the light on for whole night yet some worms were outside of bin, so i was a bit concern therefore i checked everything moisture, worm population, food, bedding and found everything ok
might be new worms exploring the new environment as i read on net that such things happens when worms are introduced in new places such as compost bin

too avoid such thing from happening again i took 2-3 dros of vinegar on my finger and slightly rubbed on the top edge of the bin.. since worms avoid vinegar they do not cross the edge thus remain in the bin.. even if the lights are off..

Not from BigTex Worms:
Hmmm, vinegar trick, sounds interesting. I will keep that in mind for next time it rains.