It's tough raising them without a companion chick. It's crop is better now. Two days of apple cider vinegar, probiotics and gentle massage. Melissa had the idea of putting some meal worms in olive oil and I think that helped too. I think what caused it is, I had a little chick feed mixed with some scratch to go outside for Nuisance and Sir Fuzzy Butt, and this one ate some scratch grains from that while running around in the kitchen.