A trifield meter works fine for lizards. Just wave it around and when the needle peaks, you've got hidden lizards around. Little known fact.
Lizards are far more harmful than people know... 90% of people with cancer were in close proximity to lizards or near places where lizards frequent in the time prior to developing cancer. The awful stuff they wisper in your ears, telling you to do bad things. Lizards are bad news, I tell ya.
So what kind of lizard do you have, anyways?