Does the restaurant keep the dumpster lids closed and the site clean? Try to keep up with the waste as best you can. Be sure to wear a mask and plastic gloves while you are cleaning and wash thoroughly with hot, soapy water when done.
Trapping the animals might help temporarily, but if it is an abundant source of food that is driving the problem, you won't have much success in reducing the number of animals until the food source is reduced/eliminated.
