Koalas are not drunk

Koalas are not "drunk" or otherwise intoxicated by their leaves. Eucalyptus leaves do not make koalas drunk. Koalas appear drunk or lazy because they have developed a low-energy lifestyle to compensate for their extremely low-energy diet. The eucalyptus leaf is very low in viable nutrients and koalas have a slightly lower body temperature and consequently a lower metabolic rate than most other mammals, to reduce the amount of energy expended per day. By sleeping 18-20 hours they conserve energy and their waking hours are used to feed, move and seek out mates during the breeding season. They do not get drunk on eucalypt leaves.