How many Wasps

My neighbour's Fatsia Japonica has been allowed to grow and has produced many more flower heads than mine which was severely cut back in September. Consequently there are many more Wasps visiting the bush which must be producing something tasty to attract them. There are probably more currently on the bush than visited my garden in Summer -in this smallish area I think I can count 15.
So silly at this time of the year but it's probably a "dead cert" there won't be any left this time next week?