你把这个短语当成一个完整的句子来看.实际可以改写成：a column of ants are triumphantly bearing home an enormous dead beetle.
bear home sth.= bear sth.home 意思是带着某物回家.这里可以看成是一个倒装句.实际是 ants bear an enormous dead beetle home.但由于这样写有点头重脚轻,所以把home提前,把an enormous dead beetle这个长短语放后面.
例句：He sent home a very beautiful and special gift.= He sent a very beautiful and special gift home.一般前面那句较常用.不觉得后面的那句话读起来更别扭么an enormous dead beetle做什么成分，