WiththesecagedcaptivesIexperimentbydaylight，whereasthefreewaspsworkintheabsolutedarknessoftheirundergroundretreat。Wherelightisabsent，colorgoesfornothing。Once，therefore，thatshehasenteredthecavern，thebumblebeeflyderivesnobenefitfromheryellowbands，whicharesupposedtobehersafeguard。Whethergarbedassheisorotherwise，itiseasyforhertoeffectherpurposeinthedark，onconditionthatsheavoidsthetumultuousinteriorofthewasps’nest。Solongasshehastheprudencenottohustlethepassersby，shecandabhereggs，withoutdanger，onthepaperwall。Noonewillknowofherpresence。Thedangerousthingistocrossthethresholdoftheburrowinbroaddaylight，beforetheeyesofthosewhogoinandout。Atthatmomentalone，protectivemimicrywouldbeconvenient。
NowdoestheentranceoftheVolucellaintothepresenceofafewwaspsentailsuchverygreatrisks？Thewasps’nestinmyenclosure，theonewhichwasafterwardstoperishinthesununderabellglass，gavemetheopportunityforprolongedobservations，butwithoutanyresultuponthesubjectofmyimmediateconcern。
Thebumblebeeflydidnotappear。Theperiodforhervisitshaddoubtlesspassed;forIfoundplentyofhergrubswhenthenestwasdugup。
Otherfliesrewardedmeformyassiduity。Isawsome——atarespectfuldistance，Ineedhardlysay——enteringtheburrow。Theywereinsignificantinsizeandofadarkgraycolor，notunlikethatofthehousefly。Theyhadnotapatchofyellowaboutthemandcertainlyhadnoclaimtoprotectivemimicry。Nevertheless，theywentinandoutastheypleased，calmly，asthoughtheywereathome。Aslongastherewasnottoogreatanumberatthedoor，thewaspsleftthemalone。Whentherewasanythingofacrowd，thegrayvisitorswaitednearthethresholdforalessbusymoment。Noharmcametothem。
Insidetheestablishment，thesamepeacefulrelationsprevail。InthisrespectIhavetheevidenceofmyexcavations。Intheundergroundcharnelhouse，sorichinFlygrubs，Ifindnocorpsesofadultflies。Ifthestrangershadbeenslaughteredinpassingthroughtheentrancehall，orlowerdown，theywouldfalltothebottomoftheburrowanyhow，withtheotherrubbish。Nowinthischarnelhouse，asIsaid，thereareneveranydeadbumblebeeflies，neveraflyofanysort。Theincomersarerespected。Havingdonetheirbusiness，theygooutunscathed。