1.) All 4 of my ducklings have this yellow sport thoward the base of their tail, it looks like feathers, but I'm not sure what exactly it is. Any know? 2.) One of my ducklings randomly bites at the air. He's not going after bugs or anything. Could he be having trouble swollowing food? It's at random times too, he'll do it for awhile, then he'll be fine. 3.) Can you eat fertile eggs? Relates to 3: 4.) I've been reading on here, the threads about inbreeding. I have sibling ducklings, and I'm not interested in offspring; 4 is about as many as I can handle right now. I'm interested in just the eggs. Would it be ok, if they breed and I collect the eggs daily? Edit: Remembered my other questions.