Count the spots on the shell, but when you encounter that many, it's probably the Asian Multicolored Lady Beetle, which is obviously a non-native insect.
The Asian Multicolored Lady Beetle was a lot more numerous around our home about 10 years ago. I saw one yesterday in our garden, but I see them infrequently in our yard. I believe this insect moved up from the southern states, and I think their numbers vary with the harshness of the winter. A couple cold winters may knock back their numbers. And the rascals do bite. It's an annoying little pinprick feeling.
From the Field Guide to Insects of North America
The Asian Multicolored Lady Beetle (Harmonia axyridis)
is an arboreal (tree-dwelling) aphid predator, coveted as a biological control in pecan and apple orchards. It was repeatedly introduced by the U.S. Department of Agriculture to California in 1916, 1964, and 1965, and to various eastern states between 1978 and 1982.
Finally, an accidental introduction took hold near New Orleans in 1988. Today it is abundant north to Quebec and west to Texas and Missouri, with scattered occurrences elsewhere.
In agricultural systems, this species may be displacing native lady beetles. They hibernate en masse, frequently selecting manmade structures in which to cluster.
Their occupation results in a permeating odor, and the beetles bite on occasion. These habits have turned them into a "nuisance pest" on the order of Box Elder Bugs.