 The same routes have been used for many generations, creating well-defined paths through the undergrowth known as "tortoise highways".On these wetter islands, the domed tortoises are gregarious and often found in large herds, in contrast to the more solitary and territorial disposition of the saddleback tortoises.Tortoises sometimes rest in mud wallows or rain-formed pools, which may be both a thermoregulatory response during cool nights, and a protection from parasites such as mosquitoes and ticks.