Crazy dog

Question
I have a year and a half old female Corgi named Maggie.  She is a highly intelligent dog and I feel I am not mentally stimulating her enough.  She will take her favorite toy (her nasty, crust ball)  Ha,ha.  She will put it behind something where she can't get to it and then stare at us until we get up and get it.  We've tried allowing her to figure out a way to get it herself, but there are some places she just can't fit into.  It's cute, but can get quite annoying when you're in the middle of something and she's knocking stuff over.  We've tried taking it a way for a few minutes when we have to get up and get it.  We've tried the "no" concept which has not effect.  Could it just be she's a problem solver and is creating a game for herself?  Any suggestions as to what I can do to help her?
Thanks

Answer
She's training you!  Why would you go get it for her just because she's staring at you - that just reinforces her for doing it, and she will keep this behavior up as long as you fall for it;-)))  Corgis are smart dogs and need a lot of mental stimulation, so if they don't get it, they make up their own little "jobs" and games, some of which the humans may not appreciate.  You might want to try getting her some of the more interactive toys, or food puzzle toys (why let her get dinner for free when she can play a game to get her food).  I order mine from activedogtoys.com, but I'm sure there are other sites.