Don't throw my ball outside!

Maggie is not an outdoor dog. I've been trying to get her to play fetch outside since we have this big new backyard. She does not comply. She just lays there on the patio. If I throw the ball she will go get it and then head for the door so she can put it back inside. She doesn't like her toys being outside. And Tucker of course is to busy running in circles chasing flies to play fetch as well...wierd dogs!