I have a recently built extension and have seen bees getting between the
sarking membrane and the Marley concrete roof tiles. I am concerned they
may find their way through an overlap and get into the void.

The main house has a black plastic comb like strip to prevent insect
access.

I am wondering if I should try sliding the bottom row of tiles up and
fitting some. Should the tiles normally just slide up? What is the strip
called? Any alternatives without disturbing the tiles - or are they easy to
move without damage?