Allah Ta‘ala only taught Nabi Aadam (‘alaihis salaam) the names, properties and characteristics of the different objects on earth and how to deal with them. Thus, it is only mankind whom Allah Ta‘ala has given the ability and aptitude to understand worldly conditions and how they impact positively or negatively on human life.
As for angels, then on account of their angelic nature, they do not possess the ability and aptitude to know and understand the human nature and how the things of the world affect man. For example, on account of man’s nature, he is able to experience needs such as hunger, thirst, sleepiness, etc. Likewise, man experiences emotions such as excitement, happiness, sadness, anger, grief, etc. On the contrary, angels do not have any such needs nor can they experience such emotions.
When an angel cannot experience the pain of hunger and thirst, the tumult of passions, the suffering from the bite of a scorpion or snake, or the exhilaration caused by an intoxicant, then how can they be in a position to give direction to man, fulfil his need or uphold the command Allah Ta‘ala in the face of worldly challenges?
Allah Ta‘ala did not mention this answer to the angels when they enquired. Rather, after creating Nabi Aadam (‘alaihis salaam), Allah Ta‘ala made him demonstrate his superior knowledge to the angels, thus allowing them to see and understand for themselves that they were unlike man who was unique in possessing the capability to administrate the earth.
(Extracted from Ma’aarif-ul-Qur’aan 1/177-180)