The eucalyptus oil could make you high if you sniff in or breathe too much of the eucalyptus oil in.
Getting high off of eucalyptus oil can be bad for your health though so I do not recommend getting high off of eucalyptus oil.
You can actually get brain damage and not just get high and the eucalyptus oil could cause you to pass out or potentially kill you.
Breathing in or sniffing some eucalyptus oil in moderation is okay and can help you sleep and help relieve anxiety.
However if you breathe in or sniff too much of the eucalyptus oil then you could get poisoned by the eucalyptus oil.
I sniff some eucalyptus oil a few minutes before bed which calms my anxiety and also helps me drift off to sleep.
But I don't try to get high off it and I wouldn't want too anyway.