 Depending on the species and where it lives , the larva either conceals itself under leaves , debris or pieces of wood , hides in a crack or digs a funnel @-@ shaped pit in loose material . As ambush predators , catching prey is a risky business because food arrives unpredictably and , for the species that make one , maintaining the trap is costly ; the larvae therefore have low metabolic rates and can survive for long periods without food . They can take several years to complete their life @-@ cycle ; they mature faster with plentiful food , but can survive for many months without feeding . In cooler climates they dig their way deeper and remain inactive during the winter . 
