In a corner of the neighborhood I walk by with dogs sometimes there's a big Tecoma sp. bush that's been in bloom a while. The thing always has at least half a dozen American bumblebees on it (easy iNaturalist observation), usually more. I think there's a nest nearby. They squeeze nicely into the flowers to reach the nectar, this flower evidently evolved to be bee pollinated. Their little bee butts sticking out crack me up.