Edible Seeds of Common L.A. Area Ornamental Tree May Be Attracting Rats

I received an email about branches and leaves coming off of a Chinese elm. Turns out that the branches that were coming down were laden with the seeds of the tree (it had recently flowered and was now going to seed). A little web-jogging turned up an "Eat the Weeds" blog page  that states that Chinese elm tree seeds (called samaras) are edible.  So why were these seed covered branches falling?  Either rodents looking for an elm tree seed meal were causing them to fall as they greedily chomped down on the seeds, or maybe even the local parrot flock -as parrots love edible seeds.

Edible winged seeds of the Chinese elm.