Yup
Jeremiah 23:24
Who can hide in secret places so that I cannot see them?" declares the LORD. "
Do not I fill heaven and earth?" declares the LORD.
Hebrews 4:13
Nothing in all creation is
hidden from God's sight. Everything is uncovered and laid bare before the eyes of him to whom we must give account.
This is one of the gray areas in Christianity.
I believe this popular view that Angels are sexless comes from the passage
Matthew 22:30 (NIV)
30 At the resurrection people will neither marry nor be given in marriage; they will be like the angels in heaven.
But the problem is, no where in that passage does it indicate angels are sexless. It just says there there will be no need of marriage. To me no marriage doesn't mean there's no gender.
The greek word for angels is "angelos" which denote more towards male. Hardly the Bible use the feminine definition for angels.
You can see a few instances.
Genesis 19 (NIV)
1 The two angels arrived at Sodom in the evening, and Lot was sitting in the gateway of the city. When he saw them, he got up to meet them and bowed down with his face to the ground.
2 “My lords,” he said, “please turn aside to your servant’s house. You can wash your feet and spend the night and then go on your way early in the morning.” “No,” they answered, “we will spend the night in the square.”
3 But he insisted so strongly that they did go with him and entered his house. He prepared a meal for them, baking bread without yeast, and they ate.
4 Before they had gone to bed, all the men from every part of the city of Sodom—both young and old—surrounded the house.
5 They called to Lot, “Where are the
men who came to you tonight?Bring them out to us so that we can have sex with them.”
The people of soddom saw those angels as "men"
Zechariah 1:19 (ESV)
19 And I said to the angel who talked with me, “What are these?” And
he said to me, “These are the horns that have scattered Judah, Israel, and Jerusalem.
Here you can see, the prophet Zechariah recorded the angel as a "he".
Anyway, all these gray areas will be answered when we meet God in Heaven,
if you still want to know by then.

even God is referred to in a masculine way.
perhaps angels can shape shift in the form of man.
but niphilim really intrigues me. after the flood, the fallen angels didnt attempt to breed with humans again?