My 19 m/o son woke up with bite marks around his ankles. look like oversized mosquito bites. they don't appear to bother him. could they be bed bugs?

Unlikely: Although your description of the appearance of the bites is consistent with bedbug bites, they are usually in a line or row and are very itchy. Other types of bugs and some diseases can also cause red bumps on the skin that resemble bedbug bites. Bedbugs usually bite exposed areas of the skin (face, arms, neck). I am not sure what the bumps are from.

Yes: This could be bed bugs, however these will usually show over the entire body surface. This could be spider bites or other insect bites. If they di not bother him, try usung an insect spray before he goes to bed for the night.

Possible: But not to worry except that is you find bedbugs, get an exterminator. For treatment, use benadryl, (diphenhydramine) Hydrocortisone and watch for signs of infection (redness, swelling, warmth, and pain). If this develops, seek treatment immediately.

Speculation: Without seeing these lesions it is only a guess as to what they may be. They could be bedbugs, but these are often linear, painful and itch like crazy. Best thing to do is to let a doctor take a look at these and then muster up an appropriate opinion.