The arrests of five boys ages 13 and 14 has broken up "the biggest burglary ring ever" in Tehama County, the Sheriff's Department reported. Officers said only about $5,000 worth of property was taken, but it was the number of break-ins--51 in all in the town of Gerber, without the help of any adult--that put the ring on record as the biggest. The burglaries began last summer. The last was at the Gerber Elementary School, where the boys are pupils. Officers said the boys readily confessed to the break-ins, some of which had not been reported.