I've had a male and female that are around 1 year old. They have 7 babies that are 5 weeks old. They are somewhat wild, living on our pond with me feeding them 2 times a day. We cannot touch or catch them. Yesterday they wouldn't allow one of the babies to eat and then wouldn't let it on the duck house last night. They other babies chase it, biting it. What caused this and how do I help?