What's the definitive way to determine if these itchy bumps are mosquito bites, hives or bed bug bites?

Looks, Located, #s: Mosquito bites are generally just a few and follow being recently outside in the evening or night. Bed bug bites are more commonly located on the legs & feet and may cover large areas. Both mosquito & bed bug bites will have individual punctures. Hives tend to cover larger areas and have more aof a rash appearance. When in doubt, see your md to be certain.

Can be tricky: There are differences btwn mosquitoes & bed bugs. Mosquitoes usually aren't out when it's really cold & they are often found outside in wooded areas. Bug beds live inside & thus are not impacted by the temperature. The itching from a mosquito bite starts right away & usually resolves w/in a few hrs. Bed bug bites may not itch but when they do it might take up to several days for this to occur. You.