Officials in the Bronx and the rest of the state will be keeping a close eye on sex offenders for Halloween.The state's parole division has announced it is beefing up its supervision of sex offenders on parole. Beginning at 3 p.m. Wednesday, sex offenders must stay in their homes until 6 a.m. Thursday. They are prohibited from participating in any Halloween activities such as wearing costumes or opening the door to trick-or-treaters.State officials say they will be making unannounced home visits and will have portable DVD players to make sure sex offenders don't have inappropriate DVDs or CDs. Officials will also be making phone calls to make sure the sex offenders are at home.Last year, officers say they made at least one visit to more than 1,900 sex offenders on parole throughout the state.