<p>Common swifts are insectivorous, feeding solely on aerial insects and spiders that it gathers in its mouth as it glides through the air. The insects are gathered together inside the throat through the use of a product from the salivary glands, to form a food-ball or bolus. <span class="taxon"><em>Apus apus</em></span> is commonly attracted to swarms of insects, as it aides in the ease of collecting sufficient food. It has been estimated that there are an average of 300 insects per bolus, and that each nest of young may receive 3000 food-balls per day. These numbers may vary based upon the abundance of prey. Among some of the most commonly consumed insects are aphids (<span class="taxon">Hemiptera</span>), wasps, bees, and ants (<span class="taxon">Hymenoptera</span>), beetles (<span class="taxon">Coleoptera</span>), and flies (<span class="taxon">Diptera</span>).<span> ("Common Swift (Apus apus)", 2001; "Swifts", 2003; Johnson, 1992; Svensson and Grant, 1999)</span></p> <p><strong>Animal Foods: </strong>Insects; Terrestrial Non-insect Arthropods</p>
- Johnson, L. 1992. Birds of Europe with North Africa and the Middle East. London: A & C Black.
- Svensson, L., P. Grant. 1999. Birds of Europe. Princeton: Princeton University Press.