You are right to be afraid of them, my good man, but remember: they are NOT invincible! Resistance is NOT futile! No indeed. We outnumber them greatly, and therein lies our collective strength. They have no chance once the Mass Awakening occurs across this planet, and it shall!
You can spot them most easily by watching their eyes, particularly when they are under great emotional stress. The eyes begin to change visibly. The pupils, which are round in a normal human eye, begin to elongate vertically, rather like a cat's pupils. The elongated pupil is often jet black, sometimes a shade of green. The rest of the eye takes on a yellowish or amber tinge. You may see the eyes shifting back and forth momentarily between a human and a reptilian appearance as the holographically generated outer appearance shifts frequencies between a fully human and a fully reptilian wavelength.
You will then begin to see the skin and outer features transforming into a scaly green covering...then perhaps back to human...then back to reptilian...shifting with the oscillation of the sheaths of consciousness.
When the shift is complete the Reptilian form is revealed. At that time raise your .45-70, point it directly at the center of the Reptilian creature's chest and press the trigger. Refuse all offers of bribes, TV appearances, fast women, free vacations, and other special favors. Show no mercy! They are just as vulnerable to ordinary weapons as a normal human, and you will have struck a courageous blow for the human race and this entire planet.