Watch the doe in this video sniffing the vegetation, etc. Most dead and/or moist vegetation readily holds lots of scent molecules. Deer, especially mature deer, seem to be constantly checking for predators (two or four legged) by using their nose.
I live and primarily hunt in the Ozark Mountains of southwest Missouri. The relative humidity is often above 80 percent in this area. Moist air carries scent better than dry air, and most scent molecules let off more odor when they are moist. This is why hunting/tracking dogs work better when there’s some moisture in the air and on the surface of the ground.
For example, most dogs have a tough time pointing pheasants when hunting in western Kansas during the midday. This is because the relative humidity in western Kansas is usually very low during the midday.
The same is true for deer. Deer living in areas with high humidity can probably detect scent from us, or our gear, easier during the early mornings or times when there is more moisture in the air than during the afternoons when the moisture content is usually comparatively lower.
Successful hunters often hunt when deer are active AND also when deer are less likely to detect the hunter. This often means hunting when the humidity is a bit lower (afternoons), with a favorable wind direction, and using good scent control.
Growing and Hunting Deer together,