During the fall, you may come across nests that look as though they have been disturbed. There is a difference in appearance between a predated nest (one that has been dug up by a raccoon, mink, fox, or other predator) and one where hatchlings have emerged freely.
The photo below shows what a successful nest looks like after the hatchlings have left. Notice that there are no eggshells strewn around, and only a very small hole remains.
However, this photo shows a predated nest. Notice the empty egg shells scattered around the area.
To see hatchlings emerging from the nest, see this short video taken by a Dundas Turtle Watch volunteer: