"Not to be sniffed at"

There's a whole row of these beauties. I discovered them the other day when I already had a blip to call my own.
My heart sank though as a spectre-thin man of advancing years, sucking on a ciggie, emerged from behind a hedge just as I was stepping up to take a shot. There I was lurking again, with a camera. If he was interested in what I was doing he didn't say. He told me he'd lived in his house for 42 years and had only once seen the door to this garage open "It was a very long time ago". "Go on have a look, there's ivy ". I pressed my face to the dirty glass then dropped my eyes down to the little hole below for a better look. The wave of musty stench that hit my nostrils shot me bold up right, retching. Why did I do that? I got my picture though.
Now, on to next smell joy of the day, washing unmentionables off the dog. She's been rolling around on the badger motorway.
What have I learned today? think before you look, it may be something not to be sniffed at.