"My squirrels simply learned to climb up to the bottom edge of the band of Tangle-Foot, at which point they leap up at an angle to catch a low-lying branch."
It is possible that if you have alluminum flashing right up to the tangle-trap (paste formula, by the way) the squirrels are unable to get an adequate launch from the flashing to jump above the gook.
[NAFEX] Tangle trap squirrel issue,
Alan Haigh, 05/21/2009