I just bought chicks 3 weeks ago. According to the date I was given, the chicks were born on April 15th. After looking at photos on this forum, I am suspecting they are older (they are covered in feathers--had to enlarge brooder, and one has red crest and cheeks. I bought a 10 lb bag of chick starter for 4 chicks, and the young men who work at the feed store told me it will last 6 weeks. Well, we're halfway through our second bag of chick feed, and we've only had them for three weeks. Were they mistaken, or am I overfeeding my chicks? If they are older..I'm suspecting my chicks may be 6-8 weeks rather 4 weeks, do I need to change their food?