So why do we not all see, or hear or smell reptilians? We are limited by our senses, and there are many gaps - frequency ranges - for which we do not have overt senses. All mysticism involves training to expand our limited senses somewhat into those gaps.
Regarding reptilians, their presence is not far outside our senses. However, they do seem to make an effort to draw themselves to the attention of those of us who can detect them. For me, I feel a piercing cold. I turn to find where it has come from, and see someone staring intently at me. That person makes very deep eye contact for a moment, then turns heel and walks away as fast as possible. If they are trapped in the same space as me, for instance a social gathering, they are easy to tease by shaking their hand or otherwise physically touching them. They are ice cold to the touch and detest my level of human heat (I am Saxon/Celtic genetically).
However, they can be very dangerous to us if they think you are a genuine threat in some way, and as their "hive" operates in 4D space when not in human bodies, they have a serious advantage over us any time they want to take it. We cannot hide from them, only from their human hosts.
They have taken over our politics, financial system, religious and mystical organisations, and most importantly, science. As they inhabit hosts, they can move from one host who loses power in an organisation, to another who gains power, although there are human family lineages that they prefer and others that they avoid.
They work through mind control and can control anyone they can get to compromise human conscience for the sake of money, power, promotion and even occult skills that have not been developed through control of the vibratory rate. Once a person has made a significant enough compromise that they have logically justified, then they commit the next compromise to cover the first, and so on until they will justify any crime against humanity through their mind controlled logic.
And we are ALL mind controlled to some degree. Next time you ridicule someone for holding a different world view to your own, ask what aspect of your mind is controlled and how it got to be controlled in that way. Self awareness, through which we detect our own compromises and close down our own "justifications", is our best defence. In other words, we just tell the truth. Now that's harder than you might imagine.