We've had a chimney on our house for 8 years but today was the first time that we have found birds in our stove. They must have squeezed through the chimney cap. There have been times that we didn't have a cap and never had any birds in the stove. The chimney for our furnace is much larger with no cap and we never had birds come through it into our house. Fortunately for the birds, I was able to catch them and release them. The first one got by me and flew around the basement for a few minutes. I grabbed the second one in the stove.