Hi there!!! I'm new to raising ducklings. I bought a pair of baby ducklings last month and one died after a heavy injury in one of his legs since he jumped off from a certain height. Just because the other one was alone, I bought another pair . The former was happy to have company but within two days both the latter died . I really don't know what the reason was because before their death, the place under their eyes turned yellow making the ducklings weak. Now since one of the duckling I bought first was alone again, I bought another pair two days ago. They were healthy when they came home but today I'm really shocked to find one among the new ones to be weak...not really weak, but he is not active like he was the day before. He quaks a little , runs and even drinks some water but is not actives like yesterday. What might be the problem ?