It seems the take home message about allotments is:
Everything will eat all your fruit and veg before you.
Cover everything up.
Kill anything that moves.
Such as the Great Pear Theft of 2014. My eldest still talks about that, she was heartbroken when we went to pick the 30 pears we'd grown only to discover some rotter had stolen in and harvested them.
It seems the take home message about allotments is:
Everything will eat all your fruit and veg before you.
Cover everything up.
Kill anything that moves.