My child keeps waking up with bites??

The other morning i noticed my son had like 4-5 bug bites. He said they were itchy and they looked like mosquito bites. I’m currently living with my mother and she was watching him the evening before while i was at work and said they were outside a lot swimming and playing and she noticed the bugs were getting pretty bad as it got later so they went inside. I too woke up with a “mosquito” bite on my leg the next morning but i was outside before i went to work so thought i must have gotten it then. The past 2 mornings i keep spotting new bites. My son sleeps with me and i haven’t noticed any new bites on me. I just changed the sheets maybe 4-5 days ago and i didn’t see any bugs, and i also checked yesterday. What do these bites look like they could be?? They started off looking like mosquito bites and now look like this after a few days.