Weird WES behavior

Question
We have had our RES for about a year.  Me is the happiest thing!  He plays and basks all day.  The other day he started digging out the rocks under his basking rock.  Now he has a little tunnel under the rock.  He still gets under there and rubs his shell on the rocks.  Do you know what he is doing and/or WHY???

Answer
Make sure you keep things in perspective and don't get to anthropomorphic in regards to reptile behavior. Turtles don't really "play", although they may enjoy certain activities like socialization with others or exploring.  

You must be sure the turtle is not female, and that it has a nice dry basking beach. A female turtle might scratch around looking for a place to build a nest. The turtle may also have fungal shell rot or some other microbe parasite, which may be causing irritation. Inspect the shell for abnormalities and make sure you are providing adequate dry basking area to dry the shell of, and are using an adequate UVB source which is no more than 6-8 months old. If these are not a possible issue, then it may be just normal scratching behavior. Turtles and tortoises love have their shell scratched from time to time.

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http://www.anapsid.org/mainchelonians.html
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http://www.allturtles.com/setup/indoorWT.php
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http://www.turtlepuddle.org/
http://www.austinsturtlepage.com