Another Dog?

I swear there's a whole extra dog behind my refrigerator and probably one under my bed, as well. I don't know what it's doing back there, or how to get it to come out and stay out.

I have 3 dogs and they have LOTS of hair. They are Labrador retrievers. They go through shedding periods twice a year. My girl seems to shed excessively.

I vacuum and sweep everyday, but it's seems like it's a futile battle. What can I do to lure that extra dog out from behind the fridge? How can I get the one hiding under my bed to scram?