in ectothermic animals, moderation of temperature, along with architectural modifications to absorb, trap or dissipate energy, maximises the rate of development, as in the case of the communal silk nests of the small eggar moth "eriogaster lanestris". the primary sources of energy for an animal are the sun and its metabolism. the dynamics of heat in animal shelters is influenced by the construction material which may act as a barrier, as a heat sink or to dissipate heat. the cocoons of insect are a case in point.