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Are crocodiles active mostly during the day or at night?

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Illustration of an estuarine or saltwater crocodile (Crocodylus porosus) with its mouth open, showing scaly skin and powerful limbs, alongside a scale bar for size reference. — crocodile Estuarine, or saltwater, crocodile (*Crocodylus porosus*), found in brackish waters from Sri Lanka, India, Bangladesh, and Myanmar east to the Solomon Islands and Vanuatu and south to Australia.

Crocodiles are primarily nocturnal animals. They are well-adapted for activity at night, possessing eyes with vertical, slit-shaped pupils that widen in darkness to control light intake. Additionally, they feature a tapetum lucidum on the back wall of the eye, which reflects incoming light to maximize vision in low-light conditions.12

While they are nocturnal hunters, crocodiles also engage in thermoregulation during the day by sunning themselves to raise their body temperature, which increases their metabolic efficiency for hunting at night.13