Snakes at early age, lizards, frogs, are fed with arthropods (like insects), which reduces significantly the number of arthropod affecting the fields, such as crickets and grasshoppers.

Due to their eating habits, reptiles and amphibians protect us from rodents such as mice and rats, as well as arthropods such as cockroaches and ticks, all of which are often carriers of diseases that can affect humans.

In most Greek ecosystems, reptiles and amphibians act as medium scale predators playing a crucial role in the structure of the food webs in these environments. Firstly, they have the potential to regulate prey populations, as well as modulate their access to key resources. For example, snakes moderate the populations of a great variety of prey ranging from birds and small mammals to amphibians and other reptiles. Another example is that of toads that regulate the population size of many species of insects, snails and earthworms. Secondly, they act as food for higher level predators playing a crucial part in the energy flow from lower to higher levels.  Lizards for example sustain a great range of predators such as carnivorous mammals (fox, badger, etc.), birds of prey (eagle, hawk, etc.) and of course larger lizards and snakes. 

While biogeochemical cycles determine the limits of nutrient flows from terrestrial to aquatic ecosystems, the movements of some organisms can partially reverse this trend (Helfield and Naiman, 2001). Reptiles and amphibians can act as nutrient transporters in two main ways: (a) through reproduction, when aquatic reptiles lay eggs in terrestrial environments (Bouchard and Bjorndal, 2000), and (b) through predation, when aquatic reptiles and amphibians are killed and dragged onto land by terrestrial predators (Veríssimo et al., 2012). Due to reproduction being a risky phase of aquatic reptile life history, during which predation is common, those processes are not necessarily separate. Reproduction-based nutrient transport can be demonstrated in the worldwide phenomena of turtles nesting on sandy beaches (Bouchard and Bjorndal, 2000). These annual events result in the terrestrial transfer of enormous volumes of nutrients originally gathered by sea turtles on aquatic feeding grounds.Nesting sea turtles in Greece may not be as many in number as in the southern hemisphere but their eggs are nevertheless a really important food source for local species, transferring a part of aquatic nutrients on land. Moreover, aquatic reptiles and amphibians such as sea snakes and frogs can transfer nutrients from aquatic ecosystems to terrestrial ones through prey they catch in the water to land predators. 

Some herbivorous reptiles and amphibians can have a profound effect on vegetation and an example of of habitat engineering is known from marine ecosystems in Greece. The Green turtle (Chelonia mydas) and the Loggerhead turtle (Caretta caretta) feed over seagrass meadows and as a result, the seagrass productivity and composition is crucially affected by these turtles' grazing (Moran and Bjorndal, 2005). Moreover, tadpoles are known to be major ecosystem engineers.  Most tadpoles are herbivorous, subsisting on algae and plants, affecting the whole composition of their ecosystem.

In reality, the way in which food resources are distributed and consumed in an ecosystem is more complex than a food chain. It is better described as a food web, with multiple linkages among the different animals and plants. 

Amphibians and reptiles represent a great diversity of species that are widely distributed across the globe and carry out a variety of functions in the Earth's ecosystems (Valencia-Aguilar et al. 2012). In many ecosystems, these groups play a key role in energy flow and nutrient cycling in both aquatic and terrestrial environments, in addition to helping control pest populations and potentially acting as pollinators and seed dispersers (Valencia et al. unpublished results).
Herpetofauna has a very special role in ecosystems and is very crucial for food grids. What's more, they play an important part in human life.