You know, I never thought of that. But they are not biological, so they do not reproduce, They were created,
True, I agree they are not biological and created.
But I haven’t found one example of a female angel in the Bible.
Demons might be different.
The two most popular theories on them is that:
1. They are the disembodied spirits of the Nephilim (Genesis 6), who were offspring of Fallen Angels and Human Women.
2. They are leftover fallen angels from Satan’s rebellion.
There was also another rebellion mentioned in Daniel 4 with a group called “The Watchers”. They are affiliated with Mt. Hermon and were supposed to guide the nations of the earth towards God, but rebelled and watched to be worshipped themselves in a nutshell.