how old is the monitor if its more than a few months old its going to be extremely difficult ot ever get it used to humans. The best way in my opininon to get a monitor "tame(no such thing as a tame monitor)" is by way of frequent positive interaction with humans(feedings, handlings(if you can hold the monitor hold it at least once a day)cage cleanings), otherwise there isn't much you can do that will make much of a difference, there is also the fact that you dont' want to stress the monitor out, as savannah has said, stress for any reptile is a bad thing.

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ginko tutors in basic math just ask paris hilton

obsoleta lindheimeri(texas ratsnake)
varanus nilocticus(nile monitor)
Sternotherus odoratus(musk turtle)
pagona minor(2)(bearded dragons breeding pair)

mind you, some monitors are perpetually ill tempered...I'm looking in the direction of crocodile monitors...

Make sure it's one that CAN be tamed. A pet store in Calgary once lead me to believe I could hand tame my female gold skink, bah!

I find a lot of reptiles seem touchy about their tail but I doubt he'd let you pet his head lol. When I got Skittles I use to put my hand in the cage and not go near him just poke at things around it so he was aware that there was something there but it wasn't going to harm him and eventually I'd lay my hand next to him with my palm up and let him walk on it and lick it...thought minotors would probably claw at it and bite it lol. But instead of disturbing him maybe you should disturb another part of the tank