Something's eating my lettuce & ant ?s

Hi - new to SFG and I am in a climate that gets hot pretty quick so I put in my lettuce (from seed) as soon as I could. The little seedlings sprouted about 10 days ago and were doing great. Lo and behold, yesterday morning I went out and half of them were gone! Some had leaves partially chewed and they were a few chewed off leaves lying next to the little stems. No bugs in sight. I put some little cardboard TP collars around the remaining ones and they were still intact this morning, but was wondering if anyone can tell me what it might be and how to prevent it. It's been a long time since I grew anything but transplanted tomatoes, but I remember in the past sowbugs eating my little bean seedlings. I don't think it's that, though. This new method keeps everything clean so not a lot of hiding places and the Mel's Mix stays fairly dry at the surface. I am also seeing a lot of ants using my grids as a "highway"; I have problems with ant colonies in my ground beds - do I need to worry about them making my beds a new home? I want to keep this organic.

Ah, we forgot to tell you the official summer night time attire: bathrobe, flip flops and a flash light. Bathrobe may be substituted with boxers and tee shirt, or summer jammies or nightie. Flashlight may be substituted with a head lamp for advanced gardeners.

The creepies and crawlers come out to feed at night. Slug, snails and sow bugs are the most common. Try to catch a sow bug and they dive right down into the MM.

Regarding ants in the Mel's Mix, I don't have the answer. I have Table Tops and the ants (Argentine) have already climbed up the legs, and I see them running along the frames. Check in the Search box for various ant control concoctions. Because I now have TT's, I am thinking about termite/ant poison. I have a cat (cats are super sensitive to any poison) so I haven't figured out how to do it. When all the beds were on the ground, I used old fashion perfumed baby talc. The newest baby powders are now made from cornstarch. I found some older baby talc still for sale at The Dollar Store/99 Cent Store. I tried DE this winter in the house - so-so.

So you find the creepy crawlers and hand pick them? I am going to the 99 cent store today because I saw a video showing that they had quite a bit of gardening materials there, so will look for the talc. What about Neem? I have been reading about it.

Yep.  Unless you have something to pick them up with... Hence the head-flashlight... 

I suppose you could use gloves or a paper towel or something...