I have 3 in one enclosure, so I'm not sure exactly which gecko it's from. I checked all of their vents and it doesn't appear to be the issue. A vet visit might be in order.

Any other ideas?
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1.1 Western Painted Turtle (Mougly, Scooter)
1.1 Albino Leopard Gecko (Daphne, Guy)
1.0 High Yellow Leopard Gecko (Sunshine)
1.1 HTCT Leopard Gecko (Rocket, Dot)
0.1 SHTCT Leopard Gecko (Tequila)