The spider probes come equipped on each probe, and walk on four legs over terrain. They can be used to see underneath certain things or explore to search for threats. Each one has a camera on its top side.
In the MovieEdit
The spider probes were not used much, only to explore certain points. Ike used one of these to explore a certain type of mushroom structure, where it accidentally completed a circuit and its circuits were shorted out. Each probe came with two spiders.