Angels have free will just as mankind does. Angels that choose sin are devils. Those that love God will be happy in heaven, otherwise those that do not love God will not be where they do not want to be, that is, with God. The fallen angels were cast out of heaven: they were eternally condemned to hell…
Baltimore Catechism
210 A. God created all things for His own glory and for their or our good.
216 A. Angels are pure spirits without a body, created to adore and enjoy God in heaven.
219 A. The angels were also created to assist before the throne of God and to minister unto Him; they have often been sent as messengers from God to man; and are also appointed our guardians.
221 A. The Archangel Michael drove Satan out of heaven; the Archangel Gabriel announced to the Blessed Virgin that she was to become the Mother of God. The Archangel Raphael guided and protected Tobias.
229 A. Before he fell, Satan, or the devil, was called Lucifer, or light-bearer, a name which indicates great beauty. He was cast out of heaven because through pride he rebelled against God.
231 A. The devil tempts us because he hates goodness, and does not wish us to enjoy the happiness which he himself has lost.