black clouds signifying rain!

My class got over at 3pm. To past time went to the top floor to see pigeons. The climate changes and man who was standing beside me told that 'pigeons have natural powers and if they it going to rain then they do not come outside'. As soon as he said it rained! The black clouds signifies it is raining. clouds during rain is black? answers to this is given in my another blog and do check it out!