TooHotorTooCold
Sweatingisawaypeoplebeattheheat.Mostendothermsdon’thavesweatglands.So,theyhaveotherways tocool down.
Dogspant.Fennecfoxesloseheatthroughtheirears.Kangarooslicktheirarms.Asthespitdries,itcoolstheirskin.It’sweird,butitworks.Ectothermscanoverheat,too.Somelizardsdigholestogetoutofthe sun.
Dogsdon'tsweat.
Instead,theypanttocool down.
Whatifit’scoldoutside?Furandfeathershelpkeependothermswarm.Oceanmammalsarekeptwarmbyfat,calledblubber.Endotherms,likebirdsandmammals,turnuptheheatbyshivering.Thiscreatesheat.Itwarmsthebody.Someectotherms,like bees,shiver, too.
Thiskangaroolicksitsarmtokeep cool.
Thisfennecfoxusesitsbigearstocool down.
Blubberprotectsthiswalrusfromthe cold.
Thislizarddigsaholetocool down.
Endothermvs.Ectotherm
Amouseisanendotherm.Asnakeisan ectotherm.
So,whichanimalshavethebestchancetosurvive?Ifasnakechasedamouseonacoolday,themousewouldprobablywin.However,thesnakeneedslessfoodtosurvive.Themousemusteateverydaytostay warm.
It’shardtosaywhichhastheupperhand.Itlookslikebothhavewaysto survive.
