Yes.  To report a player, open their player information page, click on the three bars and choose “Report Abuse”.  From there you can select the type of behaviour (insults, harassment, cheating suspicions, etc.) and submit your report.

All reports are reviewed by the Moderation Team, so please use this tool.

Is there a way to report poor behavior by another player?

A player could receive a demerit if they break one or more of the official FlyOrDie rules.

This can include abusive language, harassment, spamming etc.  See more here - 

http://www.flyordie.com/legal.html

All demerits are issued by the Moderation Team after reviewing the behaviour.