In my small sub-division of single family homes, flocking birds is a sure sign for backyard pet food.
Water is a premium in west Texas, birds don't have much choice on the matter, they go where it's found. Self awareness easily identifies which homes have water only, which have food, and which have both. Grackles and Jays will group up at homes with dog and cat food. Sparrows, doves, cardinals, thrashers, and such are signals for fresh water. All can be found on fence lines and roof tops eyeing the backyards for those pesky dogs and cats prior to alighting down for tasty kibbles and bits.
I regularly find dog and cat food in my birdbaths deposited by Grackles and Jays soaking, softening up prior to consumption. Much like dunking a cookie (biscuit to some) in a glass of milk.
I would think your cat biscuits are a lot healthier than off-the-shelf dried pet food from China, I've read numerous wicked horror stories about their non-disclosed ingredients. If I'm correct, I believe I've read stories where their bagged food resulted in deaths of pet dogs here in the states.
As for my Grackles and Jay, I've not seen one drop out of the sky dead or keeled over at my baths. My summation is; China either cleaned up their act or more people are buying domestic pet food with a surefire list of ingredients.
Maybe others have a different opinion?
Good Luck my friend.