These outdoor trash receptacles will often have some kind of cover that will both keep any waste inside the bin while also making the can easily accessible. Some of these covers may have flap doors in the front while others may simply have a lid with open sides.
Vanilla Essence: Pour several drops of vanilla essence on a couple of cotton wools. Toss the cotton wools inside the confined spaces nearest your trash can. Leave them for several days and you will notice that the area smells nice, or at least smells nicer.