Commentaire sur La Genèse 9:2

וחתכם means AND THE DREAD OF YOU, similar to (Job 6:21) “ye see a terror (חתת)." The Agada takes the word as signifying “life”, “vitality” (חיות): So long as a baby, even one day old, has life you do not have to guard it against the attacks of mice, whilst Og, king of Bashan, when dead needs to be guarded against the attacks of mice, as it is said, “And the fear of you and the terror of you shall be [upon the beasts of the field etc.].” When will the fear of you be upon the beasts? So long as you are alive (חתכם) (Shabbat 151b).

ומוראכם, this formulation is parallel to the words וכבשוה, which also referred to dominance over other creatures on earth (Genesis 1,28).

ומוראכם וחתכם יהיה על כל חית הארץ, “and the fear and dread of you will be upon all the animals of the earth.” This was not natural, as the animals for the year they had been provided for by Noach and his family had already gotten used to man as their provider. They had become so familiar with man that to be in awe of him would be a new experience for them.