Could UFO,s be using vapour trails

i was thinking if ufo,s used vapour trails we would be totally decieved

i was recently on my way back from wexford with my dad and my cousin julian in his van and we saw a plane but it was really high like a concorde goes and you know the way when they are really high they "APPEAR"(NO SMART COMMENTS)
to be going slow but the one i saw was going very fast like Mach 1 or 2 and my dad said he heard that ufo,s are using vapour trails now (dont ask me were he heard it)
but back to my point if ufo,s do use vapour trails then we would never know they were ufo,s so they could be abduckticating(my new word YAYE!) people in fields and fliing off and we would never know

[edit on 14-7-2005 by elliott reid]