Two spectacular strikes fired Posh to within five points of the automatic promotion places in League One with a 2-1 victory.
Full-back Kgosi Ntlhe and leading scorer Britt Assombalonga scored stunning goals but Ferguson was disappointed his side did not go for the jugular.
Posh failed to take a host of other opportunities and found themselves under pressure after the Bantams halved their arrears with a quarter-of-an-hour remaining.
Ferguson said: "We were excellent in the first half when we created plenty of chances and scored two great goals.
"The confidence and belief is back and we are a threat again, but after the break we stopped doing the things we had been doing well.
"It is not the first time this season that we have failed to kill off a game and that is something we need to address. A 2-1 win doesn't send out the sort message that a 4-0 or 5-0 does."