Squarespace V5 Site Server v5.13.159 (http://www.squarespace.com)http://www.raisingbutterflies.org/picture/purgeexample.jpg?pictureId=3512453<p>Mature fifth instar swallowtail caterpillars from the genus <em>Papilio</em>,<em> Battus</em>, etc. will purge their undigested food before wandering off the plant to pupate.&nbsp; If you are rearing a swallowtail in the lab or at home, find this&nbsp;purge, you need to move your caterpillar into a lunch sack, <a href="http://www.raisingbutterflies.org/anise-swallowtail/?SSScrollPosition=5820">gizmo</a>, or another suitable place to form a chrysalis.</p>