Unusual sessions in app logs

I’m seeing a number of atypical clusters of sessions in my app logs from yesterday. These are HTTP sessions unlike all of my normal (Browser) sessions and they are in quick succession of each other (within the same second or 1-2 seconds apart).

This leads me to believe they might be bots or crawlers.

However, they were all from the Debug environment, not Published. How can this be possible? I am fairly certain they were not initiated by me as none of my normal logs appear in these sessions and I have no way of reproducing them.

Has anybody experienced similar unusual sessions or might have an idea as to possible explanations?