Pesticides can also have less dramatic and noticeable effects, which may eventually result in death. Pesticides can interfere with the ability of parents to care for young, cause disorientation that may lead to increased predation, depress normal immune system function making those exposed more susceptible to disease, and, as mentioned previously, disrupt the endocrine system. Pesticides are never safe and often have far reaching and unintended effects. For example, most rodenticides cannot discriminate between rodents and other non target animals, including domestic pets. Pesticide use can affect the ecosystem as a whole.
Aquatic invertebrates are extremely sensitive to many pesticides.
Since they are near the bottom of the food chain in many wetland, estuarine, and marine ecosystems, their deaths mean less food is available for other animals in these environments. The use of insecticides has lead to the scarcity of bees and other pollinator insects in some agricultural areas. Use of herbicides kills nuisance weeds, as well as other plants that wildlife use for food or shelter. Disruption of the food chain can mean that wildlife is unable to provide enough food for offspring or develop enough fat reserves to survive through the winter or on a long migration. Another problem is that pesticides are not usually restricted to the areas in which they are applied.