Prime Desert Woodland Kestrel Nest Box

I purchased a Kestrel Nest box from Orchard Guard and Installed in a dead tree last year  It located adjacent to the Prime Desert Woodland Preserve in lancaster CA- My previous nest box is currently occupied by honey bees.    I have removed the bees twice but they always come back (see my info on ace hardware) So I bought another nest box.  Kestrels did not nest last year.  But this year it looks like they will nest-  Heave seen them in the nest box this 14 March and 20 March observed mating