Rescued duck becoming aggressive

About a month ago my husband and I went to look at a person's ac unit. We noticed that they had a beautiful white duck in their livingroom cage up with a baby pen. She made the comment that she was looking to rehome it since they were moving and had it for all most a year.  From the looks of the poor thing it had never seen the outside that much nor a pond or pool. Having 4 ducks already we decided to bring it home. She had only been feeding it chicken scratch and nothing else. The bill and legs of the duck were white and after feeding it vitmans and a mixer of scratch and feed that I feed my others it has turned to a bright orange. The duck has its strength and can get around great, my problem is in the last week she has become aggressive. I do not know what to do. She chases and bits at me and my family. There are times I throw her in the pond but she has gotten fast. I am also wondering if she is even a female. She has never quack. Please help. Thank you.

We recently welcomed a pig onto the farm from another, closing down farm.
Shes almost 700 lbs and hands down our largest pig. She spent the last 2 years alone after her siblings were butchered (and the family lost the will to finish off all the pigs) without any other pigs or company in her pen. She was angrily uncomfortable and nervous the first couple weeks and I had nothing but doubts for the safety of the situation. After a few weeks of exposure to other pigs, exploring her new area and getting used to us bugging her every day, shes doing great. However, when she was charging and snapping at me, I admit I was considering the 'other option'.

Best of luck, hopefully she calms down and integrates!

If you don't get any answers here consider posting this on a duck forum, or even backyardchickens.com (they have a lot of very knowledgeable folks that keep ducks and other fowl).

I don't keep ducks but it could be a number of things. Breed, environment, gender etc... Could also be your families behavior, I know roosters can be set off when people move/act a certain way around the flock and if folks change their behavior the problems often disappear.

I had a pet duck when I was a kid. She was a muscovy duck, known for not quacking--maybe that's what you have?

I raised her from the time she was a day old. I was her "mommy." She loved me, I loved her. When she got old enough, she laid an egg. When I went out to see her, I knew something was different before I saw the egg. She had a sparkle to her eye and a waggle to her tail. She was so proud and so happy to show me.

I took her egg away. I should have swapped it with a golf ball or something. I continued to take her eggs away, because there was no male.

She was very proud of her eggs and quickly became extremely aggressive. I think if I'd been able to leave her fake eggs, she would have had a long, healthy life with us. As it is, I never was able to get her to trust me again (I did start using fake eggs--too late.) We had to get rid of her because she just got mean.

I don't know if this helps, but it may provide some context...

Lala Glenn wrote: I am also wondering if she is even a female. She has never quack. Please help. Thank you.

With all the mallard-derived breeds, you can tell the males from the females by looking back near the tail. The males will have two or three upcurled feathers just above the tail, which the females do not.

Muscovy have bare red skin around the face, so if she has that, the above method will not apply.