The only effective way to hide ourselves is (as the Ninjutsu teaches us) to get in harmony with nature, with the surrounding environment, abandoning our human form and becoming "nothing" (nothing of relevant).
We do not necessarily have to do not be seen, heard (etc.), we must rather abandon the times and spaces that sensitively and logically can identify our essence as an object of attention.
In the particular case of learning to hide in the shadows, we must first understand what uniquely descibes a human being even in conditions of low illumination.
In this regard, let's see some classic "traces" that can reveal our presence:
The vision (active or passive) of a figure in a pose / location common to mankind (eg flattened against a wall) easily catch even the attention of the more distracted observer (the mind tends to convert even animal / inanimate forms to human figures)
The perception of articulation's movement that we are extremely accustomed to (walking, breathing, etc.) makes us identifiable even in limited visibility scenarios
The chromatic or logical contrasts in relation to the environment / context in which we are, attract inevitably the mind of those we are hiding from (eg. a few centimeters of green mimetic suit in an office)
Also only the space-time logic of the habitual / forced passages of a human being combined with the suspicion of a possible presence can in many cases be decisive in making us discovered
The regular cadence of sounds (footsteps, breaths, etc.) commonly associated with a human being (or anyway to an animated being able to harm) quickly identify us and with a high degree of certainty
At a short distance and / or in the presence of particularly sensitive persons, an intense smell (sweat, perfume, tobacco, etc.) may inevitably be an attraction for the attention
The interruption of a routine or an irregular variation of the environement can also be the cause of great logical alarmation
To these examples, of course, must be added the combination (even partial) of several elements, which, connected together, produce a precise identification of our presence / displacement.
In the next article of this series we will see how to overcome these problems and how to do not be identified.