The 'Froglife' link says it all, which refreshed my memory to when I was a young boy. I remember seeing a large frog in the bottom of our pond, thinking it was dead, I was about to fish it out on the end of a fork but fortunately (for the frog) an older and wiser big brother stepped in and explained to me that it was just hibernating, close call!.
Last time I shifted a garden storage chest in my garden, I discovered 6 or more toads under there, so I now know to leave it undisturbed.