The message
from Kay contains these words:

We're installing a wood stove this summer, which means we want to line
the chimney first.

But I notice we have a bees nest in the chimney. Is putting a liner in
likely to disturb them?

The question I'd be asking is "could that bees nest ignite my house".

They are going in through a tiny hole next to the mortar in the top
course of stones, about 6 inches below the chimney pots.

If they are building wax comb for larvae (or honey), bear in mind
that it's both flammable and melts. So if it's accessible, you really
need to get it out before introducing the heat from a woodstove chimney.
Don't be misled by the milder chimney heat from open fires. The gases
and flue emissions from a closed woodstove are seriously hotter. If the
liner you're installing is not an insulated one, it will certainly get
hot enough to ignite anything flammable in contact with it.

Also, the small mortar hole the bees are using has given you notice
that the chimney stack may have other mortar-gaps you can't see, so it's
really important that the liner reaches right to the chimney stack top.
Otherwise you could have superheated gases (or running tars, worse)
escaping through tiny chimney gaps into the loftspace. Our neighbours'
woodstove set their roof on fire that way.

Janet.