Hello, we are very new to raising ducklings and have been reading some advice from you all on this forum. I have a couple questions I was hoping to get answered. 1. On average, how old are ducklings sold at commercial stores like TSC or CAL Ranch? I've read that they don't produce waterproofing oils until they are a little older, but ours look like they are waterproof. 2. I've read some things about what the temperature of their environment should be, and try to maintain about 90*, but our ducklings seem to move around a lot away from the heat source. How critical is it to maintain a certain temperature?