The Natural History of Selborne

The air swarms with insects, & yet the hirundines have disappeared for some time: hence we may infer that want of food alone cannot be the motive that influences their departure.  * many little insects, most of which seem to be tipulae continue still to sport & play about in the air, not only when the sun shines warm; but even in fog & gentle rain, & after sunset.  They appear at times the winter thro’ in mild seasons; & even in frost & snow when the sun shines warm.  They retire into trees, especially ever-greens.