It's normal to have some wandering worms, but lots of them may indicate a problem. My first guess is air flow problems. A well balanced bin won't NEED holes in the bottom because there will be no runoff; also it's rather difficult to get enough air in via drilled air holes. The whole thing may just be too wet and not airy enough.

You could try leaving the lid off completely, and see if that helps. If so, it may make sense to leave the lid off long-term, or to cut a few massive air holes instead of having a bunch of small drilled ones.

I may try that. I have another identical bin that I may set up differently. It's odd though..Like I said it's not a lot in comparison to how many worms i have in there. Still frustrating regardless constantly moving them back into their home.

I'm dealing with wandering worms lately, too. It's only a few, less than 10 a day (out of several thousand living in the bin), but I still find it a bit disturbing. There will always be some adventurous worms checking out the periphery, but the air is good, the moisture level will even out over time as more absorbent bedding is incorporated, and it's far less than 1% explorers so I think I'm ok.

I have two 16-Gal. Rubbermaid-type plastic bins with Redworms. No holes in the bottom but the upper top half of the sides are drilled with 1/2" holes all around. My bins are outside year-round. I have no wanderers. It sounds to me like you might have an airflow problem.

I have found for me and smaller worm farms I use pantyhose to keep them in (I do not have lids on my bins) as I adjust my worm bin. I know if people who have used screening to help