No he doesn’t have to file a return and you don’t add it to your return.   

You don't have to file if you only have W2 income under 15,750 but you can file to get back any withholding taken out in boxes 2 or 17.  But you don't get boxes 4 or 6 back.

ps….FICA is the Social Security and Medicare 

Medicare and Social Security are FICA.    You do not enter your son's income on your own tax return.  If no other tax was withheld -- federal tax in box 2 or state tax in box 17, he does not need to file a tax return at all.