Genesis 30:32, How To Breed Spotted Goats

Let me go through all your flocks today and remove from them every speckled or spotted sheep, every dark-colored lamb and every spotted or speckled goat. They will be my wages.

//Here's the story. Jacob is discussing the proper wages for his service to Laban. He and Laban agree that Jacob will keep all the speckled animals of the flock.

But Jacob has a trick up his sleeve. He has figured out how to make speckled animals.

He cuts off the branches of trees, and peels the bark back to make white strips on the branches. When the animals are in heat, he places the sticks in the watering troughs so that when they come to drink, they will see spots of dark and white. There, with spots in their eyes, they mate and produce speckled offspring.

This works very well. In fact too well. All of the animals are getting speckled. So Jacob watches to see whether the females in heat are strong or weak. He puts spots in front of the eyes of the strong animals only, and leaves the weak ones for Laban.

Thus Jacob "grew exceedingly prosperous and came to own large flocks, and maidservants and menservants, and camels and donkeys."