Is there a visual difference between tick and mosquito bites?

Som?? sometimes. Usually there are multiple bites with mosquitos. A tick may still be attached at the bite site.
Usually. There are various types of ticks however most "tick bites" are smaller and less noticeable than the raised and erythematous bites of a mosquito. In addition, mosquito bites are almost always itchy whereas that is not usually the case with a tick bite.