Wasps are currently in sixth place in the Aviva Premiership table following six wins from their opening 12 games.
They return to action on Sunday with a trip to Twickenham Stoop to face former champions Harlequins.
"We went through a number of games where we were very close and not picking up the wins. It meant we weren't getting over the line," Bell is quoted as saying by BBC Sport.
"We worked on that - to try and be on the right end of narrow victories."
Bell, who joined the club in 2010, was handed the Wasps captaincy at the start of the season.