I have three four month old ducks, I purchased them from a farm that let them free range. When we looked at them you could get within six feet before they would wander away. I placed them in their Quack House five days ago. I visit them four to five times a day. I call to them then give them fresh water and scatter about a 1/8th of a cup of meal worms in the hay and crumble some in their feed. They still run to their corner and stay their and if I approach they go a little crazy running around the pen. How long will it take for them to get use to me? I want to let them free range in the back yard but afraid they won't come back to the "Quack House". Any advice would be appreciated.