SoakingUptheSun
Thinkabouttakingawalkalongacreek.Youseealizardonarock.Isitsleeping?No!It’swarmingitselfinthe sun.
Lizards,snakes,andotherreptilesareectotherms.Fish,insects,andfrogsare,too.Ectothermscan’tmakemuchheatinsidetheirbodies.Towarmup,theygetheatfromtheir environment.
Thesunshinesonthelizard.Itwarmsthelizard’sback.Thelizardsoaksupthesun’s heat.
Energyfromthesunhelpsthisdesertlizarddartand dash.
Thisdesertlizardsitsinthesuntowarm up.
HeatFromtheInside
Asyouwalk,youseesquirrels.Theyarechasingeachotherarounda tree.
Unlikethelizard,thesquirrelsdon’tneedthesuntowarmthem.That’sbecausetheyare endotherms.Endothermsmakeenoughheatinsidetheirbodiestokeep warm.
Squirrelsdon’thavetowaitforthesun.Theycanbeactiverightaway.Socanbirds.Socanyou.That’sright!Youareanendotherm, too.
What’sInaName?
EctothermcomesfromtwoGreekwords.Ektos means“outside.”Thermos means“warm.”Anectothermgetswarmthfromoutsideits body.
Endotherm comesfromtheGreekword endo. Thatmeans“within.”Anendothermgetswarmthfrominsideits body.
