Question

what helps a catterpiller to breath

Answer 1

On each side of each segment there is an oval opening called the spiracle. This leads in to a branching tube, the trachea, that delivers air to all of the segments. The Caterpillar does not actually breath, but the compression and extension of each segement as the Caterpillar moves causes the air to go in and out of the spiracles, so that oxygen can be taken in, and carbon dioxide given out.