Concrete Steps Moving Away From House
Where you live there are many basements, if you have one it is probably normal settling , in a newer home , what do you refer to as small critters? Many times foundations are back filled with rock that can settle and cause the separation for 20+ years , if this is the case and the gap is less than 3/4 inch I would use a latex caulk to seal it if larger I would contact professionals as suggested above