Trap now been out for 5 weeks. Counter reading 14 today, with 6 confirmed squirrels (either as bodies or confirmed by Trailcam), and - sadly - 3 bycatch mice. That leaves 5 "trigger events" unaccounted for.
As well as baiting according to the instructions, I've been smearing some of the Hazelnut paste on the wall higher up the chamber just above the trigger, hopefully encouraging further and deeper exploration by the Squirrels.
I caught one Squirrel on Trailcam checking out the trap bait and then having a nibble at the bark on the tree as well! Little bu99er...
Checking and rebaiting every two days now. For the first 4 weeks I was doing it daily.