One duck stays by itself

[Michael8427]

I have 11 ducks and they are in with my chickens but all the ducks used to be in a group and now one of the older ones is never with them, she is always away from them, at night she goes in the house with the rest just fine. Is this anything to worry about or is this normal ? Any thought

 

[CluckerFamily]

Have you noticed any other signs?
Slow walking, laying down more than normal, not eating, not swimming?