When chimpanzees hunt they can use weapons and can work together to direct prey in a certain direction so that the others of the group can kill them. Now, apart from the complete lack of evidence for or to the contrary, what's to stop some "space chimps" from coming down in a flying saucer and working together with tools to hunt or attack humans?
Let's say they're governed by instinct. Let's say they have no spirit and when they die then they stay dead. Would that stop a particularly intelligent and curious animal from working together with others of its kind to go into space and visit other planets? Let's work with what we already know:
1. Angels are one form of extraterrestrial
2. Some angels have bodies and spirits
3. Angels have free will
4. Angels are capable of higher thought
5. Angels are probably not made in God's image
6. Angels have visited this Earth and have interacted with us
7. We're not told if there was a plan of redemption for angels or if angels that sin are able to return to God, but we know that some chose God and some did not
8. So what's to stop other extraterrestrials with these qualities from existing and interacting with us?