Baby wild animals are found for many reasons. Sometimes mom has to leave one to escape and save the others, having every intention of returning when the coast is clear. Sometimes mom is injured or has died and the baby is out looking for her, covering the same path that mom has traveled many times. Or, and unfortunately this is most often the case, mom has been trapped and either removed to a location far from her babies, or killed by the homeowner or a shelter. There are no protections for wild mothers or babies.
If there is clearly no mother to be found, the baby needs to be fostered by a licensed rehabilitator with the skills and knowledge to help the infant grow into an adult capable of caring for themselves in the wild. As with any baby, wild babies need to be warm and hydrated with water, long before being fed anything at all. This is best determined by a vet or rehabber. Any food given before the baby's system is ready, can be fatal. Inappropriate food can also be fatal. Often, starving wild babies need special medications to protect their body systems from the resulting consequences of starvation and dehydration. A rehabilitator has the necessary skills to determine the best course of treatment for orphaned wildlife. Clicking the tab HELP LINKS will bring you to a directory to help you locate someone who can best advise you as to what immediate steps need to be taken in order to give the baby it's best chance of immediate survival.
Remember, mammals can survive 3 minutes without air, 3 months without food (sometimes longer), and 3 days without water. Hydration, next to breathing is the single most important kind of care a baby needs beside warmth. Water only is the key along with a warm and dry spot that is very quiet.