They don't like to waste time sticking their tongues into flowers that some other bee has already emptied of the sugary nectar. Look at the photo taken in the school garden. Next time you are at the grocery store look at the honey. The darker honeys are supposed to have more flavor. Most people like the lighter honeys.
Clovers are hairy stemmed to prevent ants from easily climbing the stems.
Tri folium refers to the 3 leaflets that make up a clover's compound leaf.