This Red-eared Slider had a hole dug and I think she is trying to lay eggs. I came across her at the Sequoyah National Wildlife Refuge in Oklahoma. I don't think she was in a very good place for laying eggs because she was in one of the parking areas for launching boats. I took a few quick photos and then left her alone. Maybe she knows what she is doing.
From Wikipedia: During the last weeks of gestation, the female spends less time in the water and smells and scratches at the ground, indicating she is searching for a suitable place to lay her eggs. The female excavates a hole, using her hind legs, and lays her eggs in it.
Red-eared Slider Laying Eggs This Red-eared Slider dug a hole and I think she is laying eggs - Sequoyah National Wildlife Refuge - Oklahoma