I put the bag on the back patio and soon afterwards Penny got up from her snoozing mat in the house and went out to investigate the nice smell.
Hmmm... This might need a bit of investigating...
I decided to look on the Net for info about dogs and coffee grounds.
And it looks like it would not be a good idea to lay them on the garden beds out the back where Penny can wander at will. I'll have to mix them into the compost pile, or the wormeries (three of them) or put some in the Bokashi bins (five of them), before adding them to my soil.
Here's a site with info about dogs and coffee grounds. And this is what PetPoisonHelpline says:
Pets are more sensitive to the effects of caffeine than people are. While 1-2 laps of coffee, tea or soda will not contain enough caffeine to cause poisoning in most pets, the ingestion of moderate amounts of coffee grounds, tea bags or 1-2 diet pills can easily cause death in small dogs or cats.I'll use the grounds neat on the camellias and azaleas, because Penny doesn't have free access to the front yard.