Jane Burton / Apollo rasbora {Luciosoma setigerum} territorial display with open mouth pushing sideways at rival, captive

Steven Kazlowski / Great grey / Northern shrike {Lanis excubitor} juvenile perching on branch, looking sideways, Denali National Park, Alaska, USA

Nature Production / Papuan Jellyfish {Mastigias sp} at Jerry Fish Lake, Palau

Nature Production / Nomura's / Sand Jellyfish {Nemopilema nomurai} swimming sideways, Oki, Shimane, Japan

Nature Production / Nomura's / Sand Jellyfish {Nemopilema nomurai} swimming sideways, Oki, Shimane, Japan

Nature Production / Diver with Nomura's / Sand Jellyfish {Nemopilema nomurai} swimming sideways, Oki, Shimane, Japan

Nature Production / Nomura's / Sand Jellyfish {Nemopilema nomurai} swimming sideways, with Japanese Butterfish {Psenopsis anomala} young attached to the tentacles, Oki, Shimane, Japan

Yva Momatiuk & John Eastcott / Mustang (Equus caballus) reacts to insect bites by jumping sideways in distress, summer, Wyoming

Joel Sartore / Photo Ark / Guinea baboon (Papio papio) male, looking sideways, head portrait, Indianapolis Zoo. Captive, occurs in western Africa.

Joel Sartore / Photo Ark / Common spotted cuscus (Spilocuscus maculatus) looking sideways, with tail coiled, portrait, Jakarta, Indonesia. Captive.