Is it too wet? too dry? Too hot or too cold? Those issues can cause them to abandon home. Also, do you have a light on in the room? I use that trick to keep them in the dark bin. I'd re-home everyone to the new tray. If you move them to the shed, make sure the temps are amenable to them. Good luck! escaping worms are no fun.

So which worm factory do you have, the 360 or the older style which does not have the worm ladder. The 360 with inclined worm ladder gives the worms a chance to climb back up into the lower tray. Without that ladder I can see where they would crawl up the sides of the drain tube especially if they fall into the drain tray which could be very wet which they would immediately want to leave. I never have any drainage in my 360 , any vc in the drain tub would be moist to a point where they like to stay in it. Even though I currently am using 3 working trays and a 4th tray with only paper I dont see a problem. There are always roamers and I might see on occasional worm or two on the floor, but Im thinking that to be normal.

Steve - I have the 360. I seldom have drainage, at the present time there is no drainage. These guys seem to exit as a group and pile castings on the bottom ledge to coverup with. This tray is very fool, maybe too full. I am considering harvesting the castings and starting the tray on top anew. The factory has been operating since December. Do you think the castings in the first tray should be ready to harvest?

I may be asking you a dumb question here but you dont have the upper tray bottom lined with paper making it more difficult for the worms to advance up therefore escaping out the sides, do you. Also I forget how many worms you have but that should be way more than enough time to harvest. If the bottom tray has no food or debris in it and looks dark then I would say yes , harvest.

I just started vermicomposting. I have roughly 1 kg worms, 3 layer
setup. Some of my worms, guess about 50 do slide up de sides. I have been mixing them under the scraps and shredded newspaper again - is this wrong?
Reading the previous comments, can I just leave the cover off? Living in Norway so they are in my kitchen.

Hummer - I started with 1,000 worms in December. I discovered that the drain was not completely open so it was draining ineffectively. I left it open; drained about 4 cups of worm tea (dark black, maybe from coffee grounds) and the escape problem has lessened a bit. I am leaving the drain open and it drains about 1/4 cup every 2 days.

Lovely - I think you need the cover over your bedding of shredded newspaper. Fruit flies are a constant problem. I have set up a trap for them with vinegar in a plastiwrap-covered bowl with small holes in the plastic cover.