My husband and I just began hearing animal-like sounds coming from our fireplace chimney. Well I actually thought he was overreacting, and that the sounds were just coming from our flat screen television that was hanging above our fireplace.
We didn't want to investigate too far and have some type of critter roaming our house (though I am sure our labrador retriever puppy would have loved it). So we began asking around if anyone had heard of certain animals getting into chimneys.
This is where I learned that snakes could climb walls (ew), luckily it wasn't a snake. This is where I learned squirrels can get into chimney, but it wasn't that either. A friend of ours who also has a chimney, said they were birds! I think he said they were a type of swallow.
As soon as he said bird, the noises made sense. Our friend mentioned the bird makes nests in the chimney. So that is why the sounds changed over time. First it was just a nest and one bird. Then it was a whole bunch of chirping as the little birdies hatched!
We will definitely be putting on a chimney crown or cap as soon as the birds leave!