Do we have to exit the zoo and re-enter for zoo lights? Or can we just stay?

You have to exit (Zoo closes at 4 starting November 1st) zoo lights doesn't start till I believe 5:30 seperate ticket needed and you cannot stay in the zoo you need to reenter

Zoolights is the Phoenix Zoo's largest fundraiser. A few animals can be seen but most of them will be inside their night houses as the lights irritate them. SRP is the sponsor for Zoo lights. So yes you have to exit the zoo at 4pm then pay for a ticket to re-enter Zoolights. Everyone must have ticket to enter. 2 and younger are free. Members do get a $2 discount on tickets. Sometimes Groupon will have tickets but they will be for specific days only. Phoenix Zoo website will give $2 off gate price.