Have you noticed your crested gecko sliding down the glass walls of his tank, or even falling off entirely? There are many reasons for them to lose their sticky-ness. Most of them are harmless to your pet, but it is important to learn the symptoms of illness or other disorders.
The crested gecko’s sticking ability is due to van der Waals forces, a fancy scientific force that means that certain molecules like to attract or repel each other. The feet of most geckos (about 60%) are covered with hair-like projections, called setae, that help them stick like velcro to super-smooth surfaces such as glass. These setae are arranged in lamellae – rows of these bristles – that give the underside of the foot a striped appearance. The setae are also covered in lipids (fats) that lubricate the setae and allow for easy, rapid detachment as the gecko moves across the surface. These are what give the gecko a kung-fu grip on almost anything! Scientists have used geckos for years to study van der Waals forces, in order to create new technology like tape and glue that sticks things together in both wet and dry conditions.
Some crested geckos seem to be less sticky than others. Some may rely more on their claws to stick to porous surfaces like branches, plants or even your skin or clothing. You may notice one gecko may be less likely than others to climb walls. Their adhesion isn’t perfect. Some surfaces are harder to climb than others. Sometimes they just don’t feel like sticking! Here are some reasons why your gecko isn’t sticking to walls or objects in his enclosure.
- Water spots. Even if it looks clean, glass can be covered in mineral deposits, which is a film created from hard water used to spray the enclosure for moisture. Such a “dirty” surface makes falls more likely as their toes don’t adhere as well. Using distilled or reverse osmosis water to mist your tanks can reduce hard water spots. If your gecko sticks to other things just fine, you may have an issue with buildup even if it doesn’t form visible white spots. Perhaps the glass feels uncomfortable to their feet.
- Humidity. Moisture can also affect adhesion. If the tank is dry, they may have a problem, either from the physical lack of water on the surface or the lack of body moisture makes them less likely to stick. If there are droplets of water on the glass after misting, this can interfere with the bond of their setae to the glass. As long as they have plenty of branches and things to climb on, I wouldn’t worry if they don’t climb on the glass much.
- Stuck shed. An imminent shed can easily cause a lack of stickiness. When my geckos are about to shed, it feels like my hands are covered in teflon – they slip right off! If the gecko feels slippery when you handle him, then it’s likely an upcoming shed. Some geckos just seem to be less sticky and have problems shedding, especially when younger. Lack of adhesion could be from built up shed on the toepads. You can try leaving in a small but rough textured rock in the enclosure, or gently clean the feet yourself with a wet Qtip using a rolling motion up and down the bottoms of the feet. Keeping the tank too damp for too long can interfere with the shedding process. Being too dry for too long does the same thing, leaving little bits of skin stuck to his feet which keeps him from sticking properly.
- Illness. If your gecko seems lethargic, has chronic stuck shed and won’t stick to anything, then you probably have a sick gecko. You should take him to a vet at this point to get him checked out. Whether their health directly affects their adhesiveness is unclear. They may just be less active and decide not to stick so they don’t further injure themselves in a fall. Some say that not sticking is an early sign of Metabolic Bone Disease, and it is a possibility. It’s not a sure sign of MBD, but many MBD geckos have this problem. The other factors above are much more likely the cause of him not being sticky.
- Neurological issues. If your gecko seems to be off balance, and it’s not dizziness from recently slipping down the glass or falling, this may be a neurological problem. Again, a vet trip is in order for professional diagnosis.
- Nutrition. If your gecko has been on a poor diet (only crickets, baby food, etc) then it could definitely be from a lack of vitamin A or other nutrient. An improper diet can cause a lack of stickiness if the body isn’t absorbing the right nutrition and hydration to shed properly.
- Material. Plastic tubs, especially the opaque soft ones by Sterilite and other brands, seem to be less favored for sticking than glass terrariums or harder plastic Kritter Keepers.
- Size. Baby crested geckos under 6 grams seem to have the most trouble shedding, and therefore may not stick as well as an adult. Conversely, very large crested geckos may also have trouble sticking due to their extra weight. However, geckos of any size can still stick pretty well, even upside down!
It is unknown if this is because they can’t see out of it or if they don’t like the material as much. This tidbit of info is useful if your gecko likes to sleep upside down on glass, often leading to Floppy Tail Syndrome (FTS). A plastic tub is useful because they are less likely to sleep while sticking to it.
If you see your crested gecko stick to some things but not others (besides the glass or plastic issues above), then he’s probably just being goofy. That’s fine! Sometimes geckos can just prefer to be different. You could try keeping the enclosure vines and furnishings low to the ground so he won’t be hurt if he falls. As long as there is no underlying health issue, it’s ok if your gecko isn’t sticky!