Below is an anti Bird and rain (ABR) cowl. Click here to view more cowls
A bird creates a nest in a chimney by dropping nesting material down the flue until it stops, then building up from there. This may stop at bottom or near the top. Therefore it is possible to have the entire flue filled with nesting materials.
The nest needs to be broken up and removed from the base of the flue. It is not necessary to break into the chimney to remove a birds nest. Fitting a chimney cap on a disused flue or a cowl/bird guard to a flue that's in use will prevent birds from nesting in it.
Bees can also take up residence in your chimney, flue or pot. Any honeybees will be re-homed in a suitable hive if at all possible and blockages removed.
Squirrels may also use your chimney to nest in, we can also remove the offenders and remove the nest.