I'm using the Dollar Tree zip ties too, to band chicks for identification. Mostly just banding them pink or blue as I know what's a male or female, so I can get a quick, easy count of how many of each I have, and the ones that kids in my family have picked out for 4-H/showing each have a tie on them so the kids know which bird is theirs. I clip the end very short, so there is no tail to annoy them as they walk or get pulled on, but there is a tiny bit of room so I can expand it a little if I need to. I put them on as loosely as I could without them falling off, and the chicks seem to be doing ok. I will take them off as they grow too big for them, and eventually go to regular leg bands, I just don't have any or the cash to get them at the moment.