Your "Flock" is a swarming pack of European Starlings. These are exotic, non-native species to the New World that were first imported to Central Park in New York City in the Late 19th Century. They have spread from the tip of Alaska to the tip of Tierra Del Fuego in South America, much to the DETRIMENT of MANY New World bird Species. That being said, they are quite cute and rather pretty, especially in Summer when they turn an irridescent black with bright yellow bills and feet. In Winter they get a speckled appearance as shown in your photograph, Triss. They will QUICKLY eat EVERY speck of suet you have and then vanish without a trace until about five minutes after you refill your suet. They then return in force and bring more friends.