▁doubles . ▁ ▁The ▁inc ub ating ▁be es ▁do ▁not ▁have ▁a ▁target ▁temperature ▁for ▁their ▁bro ods . ▁They ▁will ▁continue ▁to ▁inc ub ate ▁bro ods ▁despite ▁the ▁ambient ▁temperature . ▁At ▁ 3 0   ° C , ▁the ▁queen ▁will ▁inc ub ate ▁the ▁eggs , ▁even ▁though ▁at ▁ 1 0   ° C , ▁she ▁only ▁ra ises ▁the ▁bro od ▁temperature ▁to ▁ 2 6   ° C . ▁However , ▁it ▁has ▁been ▁observed ▁that ▁the ▁amount ▁of ▁therm og ener ation ▁that ▁occurs ▁at ▁the ▁ab d omen ▁is ▁reduced ▁when ▁the ▁ambient ▁temper atures ▁are ▁greater . ▁ ▁Inc ub ating ▁be es ▁do ▁not ▁continu ously ▁warm ▁the ▁bro od . ▁Because ▁of ▁the ▁inten se ▁met abol ic ▁cost ▁of ▁war ming ▁the ▁eggs , ▁they ▁must ▁occasionally ▁take ▁breaks ▁to ▁feed , ▁at ▁which ▁point ▁the ▁bro od ▁returns ▁to ▁ambient ▁temperature . ▁Bro ods ▁will ▁h atch ▁whether ▁or ▁not ▁they ▁have ▁been ▁inc ub ated ▁consist ently , ▁and ▁the ▁new ▁worker ▁population ▁will ▁assist ▁in ▁inc ub ation ▁for ▁the ▁next ▁generation . ▁ ▁Th erm or eg ulation ▁in ▁flight ▁ ▁Y ellow - fac ed ▁b umble be es , ▁like ▁most ▁b umble be es , ▁use ▁therm or eg ulation ▁to ▁maintain ▁ ▁stable ▁body ▁temper atures ▁several ▁degrees ▁above ▁the ▁ambient ▁temperature . ▁At ▁rest , ▁b umble be es ▁have ▁temper atures ▁close ▁to ▁ambient ▁temperature . ▁To ▁generate ▁power