Are there plenty of places for the gecko to hide or is the tank pretty bare? You might try to see if leaving crickets in overnight helps since they are nocturnal anyhow. What about the temperatures?
Are you positive the gecko is a he?
Are you positive the gecko is a he?
Even if this was a female she or he shouldn't be digging. Girls are egg gluers so they stick their eggs up high glued to something.
Males or females don't dig. It's off behavior. Perhaps because of his past this is a learned stress behavior. I have no other ideas of why he'd be digging though.
On that note, are you sure it is a Tokay?
Not trying to be a butt or anything, that is odd behavior for a tokay.
Maurice Pudlo
From those pictures I think female. Are you relaxing or the gecko?