Last leaf left

This snail thought it was a good idea to choose a leaf of a small tree as resting place for the winter. I'm not sure that he really thought things through, as ALL the other leaves of the tree have fallen to the ground and are now being transformed into building blocks for future life. That made me wonder whether the snail realized that this leaf would be the one staying the longest on the small tree or whether he transmitted some substance to the leaf so that it would NOT fall at all? Both hypothesis seem ridiculous. It must be pure luck then!