Black beauties: ravens in the yard

Three ravens like to come sit on the back fence in our yard. They just hang out for a while, not doing much of anything. They don't go to the feeder. Once in a while, one of them lets out a croak. Sometimes, one or more of them sleeps with one foot up. We don't even know if they're the same three ravens, or if ravens just like to hang out in groups of three. One of them will leave, or two of them, or even three, then come back one at a time. Then, eventually, they fly away. (Note. Only two of them appear here. One of them flew away.)