So, do you want to know what my handler discovered in that hotel room in Ocean city, MD where our trainer had hidden a vile of about 50 bed bugs for me to alert to?
Do you remember how I did not alert to its source.  Yet I had many unusual changes in my behavior throughout my inspection of this room.
And do you remember how the AC was on full blast?  And how I shied away from sniffing it?  And how my handler was so perplexed?
So here it is:  the trainer then turned off the AC and asked my handler to have me sniff out that area again;  I sniffed out the whole AC unit and suddenly had a whiff of that scent of bed bugs.  I sweeped back and forth like us beagles like to do, so as to hone in on the exact location.  I wasn’t satisfied,  so I jumped on the chair nearby, tnext on the table which allowed me to reach out over the AC.  Bingo!  There was that scent, as heavy as can be:  I pawed cautiously (that is my alert)  as I did not want to fall on that AC unit.
My handler was awed.  And my trainer more than satisfied.
Now how can you learn this on your own without the expertise of a certified trainer.