identify please

outside our window is a sycamore this morning i noticed at what looked to me to be a very large cuckoo spit,only this was as large as a saucer on looking close it appeared to have little grubs inside,after about an hour this disappeared,maybe because of the rain im not sure,surfice to say ive not seen this before anyone else seen this

 

You are experiencing hallucinations after too much of over the New Year :D

Seriously though - no idea, sorry.

 

What colour were the grubs? David.