Is there a rule

[Huskerblue]

Yesterday in an NAIA college game, there was a runner on 1st. Batter squares early to bunt, and third baseman and second baseman(no this is not a mistake), come charging hard and end up about 10 feet in front of the pitcher's mound before the pitcher delivers. The manager for the offense said they cannot do that. I looked dangerous to me, but I cannot find a rule that prevents the defense from doing that. Is there such a rule? And what is the penalty?