I have 2 budgies, to me they are parakeets. I inherited them from my grand daughter who was unable to keep them. One is white the other blue. The blue one has a growth on the cere is approx 3/16th of an inch and is hard, looks like a horn. I don't handle these birds at all and they are in a flight cage. the second issue is lately the white bird has become "aggressive" does not do any damage to the blue bird but chases it constantly around the cage. they have been together since I took them in about 2 years ago and this behavior is new. guestimate they are 3 +- years old. Any thoughts on the cere and the aggressive behavior?