I guess the other recommendation would be to give them some chick grit (which is really just very coarse sand) so that they can digest some of those other things that they are bound to pick at and eat. And then you can give them all kinds of treats and not worry. It may be that they are seeking something like that, and the pine chips is all they have available. Also elevate your feeder to chick shoulder height - mine would fill with bedding and who could tell what was what - if you haven't done that already. I used a coarse sawdust/pine chip bedding that I get from a local sawmill, same thing I use in my stalls, from the get go with my chicks and they all did fine.