I have a red eared slider that is approximately 4 years of age, about 7" (17.5 cm) in girth and about 10" (25 cm) in length. It has an above water basking area that is accessed by a ramp. The basking area has three flat rocks approximately 6" (15 cm) in diameter surrounded by pea gravel. My turtle has recently began using it's hind legs to throw the pea gravel over into the water. In the last two days the turtle has manipulated the large rocks over the side of the platform into the water. Again there are 3 rocks, approximately 6" (15 cm) in diameter, 1" (2.5 cm) thick, weighing a couple of pounds (over 1 kilogram) a piece!
I know the turtle is incredibly strong, but what's going on? I don't know why my turtle is behaving this way. Oh, I'm not sure of gender (OK, I'm not an expert) but he/she has never been around another turtle. Might this be some sort of "false pregnancy" behavior in that it's searching for sand or a softer material than pea gravel to lay eggs?
Otherwise, my turtle is very healthy and behaving as always otherwise. Any help would be greatly appreciated.