I woke up this morning with what appears to be a bite on my arm, it is red and swollen hot to the touch is it a bite or could it be a hive/pimple?

Not diagnostic: Without examining it, it's not possible to make a diagnosis. If there is spreading redness,heat,pain and/or tenderness,Antibiotics may be needed for a secondary bacterial infection of a bite or an early boil. Get it checked by a physician if you observe these findings. In the meantime apply warm compresses and apply an antibacterial ointment like bacitracin.