UDP question

Please let me know if this doesn't belong here, I think because its a little technical it should be alright.

We have an assignment in school to come up with an alternative way to scan UDP ports with accuracy outside of negative checking. so my idea was that I could leverage a response of some sort from based off of rate limits from ICMP packets flooding the port. I figure if there's some sort of response... maybe not direct communication but something like a delay or failed ping that would come from rate limiting... then I can use that to identify if a port is open because no one would rate limit a closed port.

How far off am I in my theory, what do I need to read more about?? Thanks in advance!!