Malpighian tubules are the excretory organs of insects. It opens at the junction of midgut and hindgut (ileum) in cockroach. Malpighian tubules absorb excretory substances from haemolymph and fat bodies and pass into the proctodaeum. The excretory product of insects is uric acid related with water conservation. These tubules are concerned with homeostasis, osmoregulation and excretion,Respiratory organ of insects istracheae, which opens outside by ten pairs of spiracles, present in thoracic (2 pairs) and abdominal (8 pairs) parts.Endocrine glands of insects consist of corpora allata, corpora cardiaca and prothoracic gland, which regulate metamorphosis in insects through different hormonal secretion.
Excretory organ of frog is kidney (mesonephric), large urinary bladder, excretion ureotelic.