These little guys have mighty big mouths, and for good reason. Find out why.

• It takes an adult yellowhead jawfish about 8 hours to construct a new burrow. Jawfishes stabilize the entranceway to their burrow with rocks and shell fragments.

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• To protect their turf, jawfishes occasionally spit mouthfuls of sand at small intruders.

• To mix and aerate their eggs, males occasionally partially spit out and quickly suck clutches back in, a behavior known as churning.

• Jawfishes have been documented sharing their burrows with, surprisingly, moray eels.

Related Reading: Why Do Fish Travel in Schools?

• Before bedding down for the night, yellowhead jawfishes cover the entrance to their burrow with rocks to prevent home invasions.

Crazy about fish and other marine life? Learn more interesting facts about the creatures in the ocean, from the tiniest nudibranchs to the largest fish on earth, the whale shark, at the Marine Life section of our website.