[Arid_gardener] Question from Home-Hort WWW page

[LDLMSL at COX.NET]

Mary Sue
85254
LDLMSL at COX.NET

We have grown tomatoes for years and never had this problem.
The 10 plants are in a raised bed and the ripe or ripening fruit is being eaten by something that we can NOT see.  Basically, the whole planter is now encased in shade screening and there is just NO way for anything to get in.  We check it many times a day and have NEVER seen a bird or worm or bug of any kind inside the planter.  There is nothing coming in from under the planter, either.
Can you think of anything that could be "invisible" (sounds crazy) and eating our tomatoes?  
We have NOT used any kind of pesticide or dust of any kind as yet and would hate to.
Thank you so much in advance for any help.
Oh, we feed the quail and hummingbirds and other birds on the complete other side of our yard.