8 Common Mistakes New Reptile Owners Make

This page is for anyone in their first year with a lizard or snake, or about to buy one. Most of the mistakes below are setup errors made before the animal arrives, and each has a specific, cheap fix.

Mistake, consequence and fix

Mistake	What it causes	The fix	Species most affected
Heat source with no thermostat	Burns and temperature swings; “hot rocks” frequently burn larger animals (MSD; VCA)	Every heater on a thermostat, screened from the animal (MSD); check both ends daily with digital thermometers, because thermostats drift (RSPCA)	All, especially basking lizards such as bearded dragons
No UVB, or UVB through glass	Vitamin D3 deficiency and metabolic bone disease: weak muscles, softening bones (RSPCA)	UVB lamp inside the vivarium; no glass or plastic between bulb and animal (RSPCA; VCA); replace when the maker says, VCA suggests about every six months (VCA)	Bearded dragons and most other day-active lizards, plus tortoises (MSD)
Undersized enclosure	No usable temperature gradient, stress, and glass tanks that lose heat (MSD)	Adult bearded dragon at least 48 × 24 × 24 in (120 × 60 × 60 cm); adult leopard gecko at least 24 × 16 × 12 in (60 × 40 × 30 cm) (RSPCA)	Bearded dragons, which VCA says need 60–100 gallons as adults (VCA)
Loose substrate for juveniles	Swallowed substrate can block the gut (impaction) (VCA; RSPCA)	Paper, slate or set clay for juveniles. The RSPCA only approves sand/soil mixes for healthy adults, and never calci-sand, bark, walnut or corn cob (RSPCA)	Bearded dragons and leopard geckos
Live prey left in the enclosure	Uneaten crickets bite the reptile (RSPCA); live rodents injure snakes (MSD)	Remove uneaten insects; feed snakes frozen-thawed prey with tongs (RSPCA; MSD)	Leopard geckos, bearded dragons, all snakes
Handling too soon	Stress, refused food, and snakes bringing up their meal (RSPCA)	No unnecessary handling for the first week; wait 48 hours after a snake eats; sessions of about 10–15 minutes (RSPCA)	Snakes, particularly ball pythons
Wrong humidity	Too dry: stuck sheds. Too wet with poor ventilation: respiratory infection (RSPCA; MSD)	Hygrometer at the cool end; fix high humidity with ventilation, not by sealing the vivarium (RSPCA; MSD)	Ball pythons (too dry or too damp); bearded dragons and leopard geckos (too damp)
Poor Salmonella hygiene	Even healthy reptiles carry Salmonella; the tank water, food and equipment spread it (CDC)	Wash hands with soap after every contact and clean equipment away from food areas (CDC)	All reptiles

Temperatures and UVB: the two numbers to get right

Temperature and UVB do the most damage when wrong, and both differ by species.

Species	Hot end	Cool end	Humidity	UVB
Bearded dragon	100–108°F (38–42°C) (RSPCA)	72–79°F (22–26°C) (RSPCA)	30–40% (RSPCA)	High-output 10–12% tube over up to half the vivarium length (RSPCA)
Leopard gecko	Basking spot on stone (RSPCA)	75–79°F (24–26°C) (RSPCA)	30–40%, plus a damp-moss humid hide (RSPCA)	Lower needs than many reptiles (MSD)
Ball python	Basking zone on a thermostat (RSPCA)	75–79°F (24–26°C) (RSPCA)	50–60%, misted up to about 80% (RSPCA)	See the UVB guide
Corn snake	Basking zone on a thermostat (RSPCA)	68–75°F (20–24°C); night can drop to 61–68°F (16–20°C) in a heated home (RSPCA)	40–50% (RSPCA)	See the UVB guide

UV output falls as a lamp ages even while it still glows, so the RSPCA says to check light levels regularly and replace the lamp when the manufacturer recommends (RSPCA). VCA places the bulb within about 6–18 inches (15–45 cm) of the animal for a bearded dragon (VCA). Albino and other pale bearded dragon morphs need less UVB: the RSPCA gives a gradient from 0 in the shade to a maximum of 3.0 in the basking zone for them (RSPCA). The reptile lighting and UVB guide covers lamp types.

Salmonella in the house

The CDC says reptiles often carry Salmonella in their digestive tracts, and you don’t need to touch the animal to get sick, because tank water and equipment carry it too (CDC). Its rules:

• Children younger than 5 should not handle reptiles or touch their enclosures (CDC).
• Wash with soap and running water after feeding, cleaning or handling; hand sanitizer with at least 60% alcohol is only a fallback (CDC).
• Never clean habitats or equipment in food preparation areas. If you can’t clean outdoors, a laundry sink or bathtub is acceptable when disinfected afterward (CDC).
• The CDC suggests considering another pet if the household includes young children, adults 65 and older, or anyone with a weakened immune system (CDC).

Mistakes that come later

• Skipping quarantine for a second reptile. The MSD Veterinary Manual recommends quarantining new reptiles for 3–6 months before they share air or equipment with existing animals (MSD).
• Spinach for bearded dragons. The RSPCA says to avoid it because it prevents calcium absorption (RSPCA).
• Sealing vents to raise humidity. MSD says reducing ventilation to hold heat and humidity frequently causes skin and respiratory disease (MSD).
• Panicking over a ball python fast. The RSPCA says royals are known for going off food, sometimes seasonally; weigh it regularly so you can tell a normal fast from real weight loss (RSPCA).