Jackdaws love nesting in chimneys! You may find twigs falling down your chimney or you may notice Jackdaw activity around the chimney pot.
Jackdaw nests can fill the entire flue, they are an obstruction to the escape of combustion gasses and are highly flammable.
After clearing a birds nest I check the full length of the flue with cctv equipment to ensure the complete removal of nesting material.
It is an offence under the wildlife and countryside act 1981 to remove an active nest, therefore I only remove nests from August to March.