Greenwich health officials say a private school student did not realize the implications when bringing a live bat to school to show to a science class. The episode at the Whitby School last week prompted a rabies test of the bat, which was killed by an exterminator. The test came back negative Saturday. School officials told the Greenwich Time that they notified parents about the episode and again when the test came back negative. A school spokesman said the student and the student’s parents thought the bat would be an interesting thing to study but did not think about the possible hazards. In 1995, Greenwich eighth-grader Maria Fareri died of rabies after being exposed to a rabid bat.