lettuce seedlings mysteriously dissapeared

So I have 4 squares of lettuce seedlings right next to each other. The are direct sown, newly germinated and still only have 2 leaves. This morning, 2 entire squares have gone - vamouse - nothing left, not a wilted brown anything, not a stalk, not a leaf and not a footprint. I am fenced for deer and rabbits.

The one thing I did notice when I was picking lettuce from my older plants last night for dinner, was slaters or pill bugs, and ladybugs (which are good guys I think). I know some bug is snacking heavily on the left overs of my broccoli - but all I have seen on that is a green soft caterpillar. I have figured out that the green guy is not good for my broccoli and pick them off and feed them to the fish (tank), is it possible that the slaters have eaten my lettuce seedlings? I am trying very very hard not to use pesticides, but right now I am still learning what bugs are good and which ones aren't.

any thoughts?

I have diatomatious earth in the garage, but have been hesitant to bring it out because I am worried about hurting the earth worms. Ah, the dillema.

Thanks for any insight

Pill bugs eat mostly decaying matter. See here.
There is a lot of good info on the web about insects benefiting the garden.
I would guess a rodent (vole) or rabbit, it's pretty impressive that all that lettuce is gone just like that. If it was me I would re sow.

last night - but they left evidence. I will be on the war path now because - well just because! I am sad, but cheered mysel up by putting in another garden - 8x4 - the last one I promise my self. That brings my total to one 6x4, three 8x4 and one 4x10. perhaps I could use another one lol

I had exactly the same thing happen! I decided it was cutworms, and that there was nothing left because they were tiny fragile seedlings. But it could have been squirrels or chipmunks too in my case. And I have a grub infestation.

As a result, I decided to start my lettuce indoors and transplant out when they have a better chance of surviving. Also I will be adding cutworm collars made from 2 liter bottles cut into rings.

Pill bugs are very clever. They have the reputation of only eating decaying matter. However, I am certain that they ate holes in my strawberries, because I watched them in the act. And there is plenty of evidence that they do, indeed eat vegetable material.

Don't be fooled. They can and do eat your veggies, although their bread and butter is decaying matter. I have no idea how to control them, I just know they aren't the innocuous bugs they would like us all to think they are.

that is one of the best things about this forum, besides all of the things I have learned already. None of my friends are entheusiatic at all about my vege garden (at least until I share the bounty I am sure), but when something happens to your baby lettuce (or whatever) someone else has usually had it happen. That is a nice comfort - even if it doesn't bring them back but I did notice that one lone seedling has made it out of 4 squares of 9 - so I am thinking it made it to the 'too big to destroy' size because my big lettuces in the square next door is doing very well, and has done for weeks - yay