One possibility for any black balls in fecal matter is blood clots. If you have bleeding in the stomach or small intestine, the blood will clot before it comes out. If you see this, it is wise to see a doctor. Of course, there are other possibilities like foreign objects or stool that had been partially impacted but somehow worked its way loose, but if you have any doubts or concerns, see a doctor.
Its black specs
its the intestine. its black because of feces :P
dark almost black
There are different colors of feces for many different reasons. Black feces indicates blood and you should see a doctor immediately. Green feces may indicate that you are a certain food dye.
Birds do not urinate as people do. Their urine is excreted with their feces. Their feces is actually brownish-black in color and the white you see mixed in with it is the "urine", which is actually very concentrated urea, not urine itself. Also, usually the bird feces can be white with a black spot or dot, not the other way around.
The probability of a black ball in bag 1 is 4/12 = 1/3. If you add 3 black balls to bag 2, it will contain 5 black balls out of 15: the probability of a black ball being 3/15 = 1/3.
I am assuming that what you are talking about is the quest where you have to get BLACK balls of wool and give it to the farmer. You get black balls of wool by shearing the black sheep, then spinning the wool on the spinning wheel.