Hello, I just incubated my first 4 chicks, totally new to chicken ownership. When the chicks were about 5 days old one started sneezing. That one has progressed to more sneezing over the past week but otherwise healthy and very active. 2 other chicks occasionally sneeze but that is the only symptom. They were on paper towels, just switched them to pine shavings today (12 days old). They are in a room that is about 73 degrees with a sweeter heater. Any thoughts? Thank you!