Some years ago I hung a ceiling fan on our patio. From the fan to the patio roof is about an 1 1/2 to2 inch gap. This spring a pair of small black, gray and white birds built a nest inside the fan. Sorry, but I was never able to definitively identify them. But the fledglings grew and became noisy and more active. This afternoon there was tremendous chirping and screeching in the backyard until we witnessed a blue jay having either the mom or dad for lunch. Despite never seeing the fledglings leaving the nest it is now empty. My question is could the blue jay have raided the nest and killed the entire brood? I have not seen the surviving parent returning to the nest. I never knew blue jays could be so aggressive and carnivous.