i rescued 4 baby ducks and purchased one brown duck from store. I introduced them to the back yard lake last night and they seem to be doing well. 4 of them used the ramp i built for them and came back to the my yard. the brown duck didn't follow them stayed in the water chirping. the other ducks seem not caring at all and didn't want to help her or responding to her chirp. she has been in the water for hours and i thought she may figure out how to to claim up the ramp. No luck. I am not sure why the other ducks ignoring her. I had 22 ducks.. This is very unusual. any advice?