Thats why its so important to break the food down small in the first place. Otherwise the bacteria cant break it down very quick. As a rule when I add new food worms have moved up to it in 2-3 days

I had it cut into 1/2-1 inch chunks, not whole. They just seem a bit slow getting up there. The bin was a bit warmer than I am used to- 83 degrees. Maybe this initial breakdown needs another day or so before they invade!

Thanks!

Check around the edges of the tray, too. I always find more worm activity there, castings building up faster there, etc. They seem to like to hang out at the edges and also use the edges to travel up and down between trays - perhaps because there's a bit more oxygen there, or because they like the moisture that condenses on the plastic sides.