Malaikah (Angels) & Jinns (Invisible Beings)
Angels and their creation
The Quran teaches that angels are one of the creations of Allah ﷻ like humankind and jinns but they do not have a free will like the latter two. Allah ﷻ informs us that they do as they are told: (Al Quran 16:49-50) every beast that moves, and the angels: [even] these do not bear themselves with false pride: they fear their Sustainer high above them, and do whatever they are bidden to do - Elsewhere in the Quran it is mentioned they never neglect the duties assigned to them (Al Quran 6:62) unlike humans and jinns who can disobey. One of the prophetic hadith defines their creation: “The angels were created from nur (light), the jinn from smokeless fire, and Adam from what was described to you (i.e. in the Quran).” 
Nur in Arabic means ‘light’, however; this light is not the same that is observable through a naked eye. It could be a very subtle or concentrated form of light, which cannot be grasped by our normal sense of sight. In the Quran and Prophetic hadith, the angels are referred to with the Arabic term malaikah, which is plural for "many angels", while malak is a singular angel and is related to similar term in Arabic called maalik which means "king" or "sultan" implying authority and power or energy. In addition to their creation from a form of nur (light) we can assume that they might be created from a subtle form of energy that moves within the electromagnetic spectrum within our universe. It may be that they belong to a frequency within this spectrum, which cannot be detected using our normal sense perceptions. For instance, birds can view the ultra violet rays, an electromagnetic radiation, within the sunlight, which are not visible to human eyes, due to special receptors carried by birds. Knowing the special ability of theirs, we can understand the prophetic hadith that teaches angelic presence is felt by birds: “When you hear the crowing of the roosters, then ask Allah of His bounty, for verily they have seen an angel. When you hear the braying of a donkey, then seek refuge in Allah from shaitan, [satan the rejected] for, verily, it has seen a Shaitan (a jinn devil).”  Just as exposure to UV-rays at an intense frequency can cause humans to experience Photokeratitis, a painful eye condition, it explains why angels remain invisible to us in their normal frequency mode while in a stronger frequency their appearance may cause us harm. This may explain the fact that one day Hamza ibn Abdul Mutalib (radiAllahu anhu) asked Allah’s Messenger ﷺ that he wanted to see Archangel Jibraeel (Gabriel) (alaihi salaam). The Messenger ﷺ pointed towards the Kaabah, but Hamza (r.a) could not bear the sight and fell unconscious.
 Riyad as-Saliheen Book 19, Hadith 39
 It is the range of frequencies (the spectrum) of electromagnetic radiation and their respective wavelengths and particles.
 Jami at-Tirmidhi 3459
 The paternal uncle of Prophet Muhammad ﷺ, was martyred in the Battle of Uhud.
 Shifa, 1:362; Suyuti, al-Khasais al-Kubra 1:311 - Nursi 2010