Another English -> Chinese Characters question

Hi Gang. I’m looking to get the Chinese characters for the following phrase:

“Happy Birthday, Lowly Rodent”
Google gives me this:
… but I want to make sure it all actually makes sense.


PS-- this will be written horizontally. So proper left-right orientation would help.


A lowly rodent

Back-translating it gives you “I wish you a happy birthday, humble rodents.” Seems promising (if, as I seem to recall, Chinese does not usually indicate pluralization).