With more surface area to their volumes than adults, newborn rattlesnakes heat and cool at faster rates. Piling into a wad reduces the amount of air-exposed skin and may blunt temperature swings. At its most efficient, cooler babies from the bottom of the wad clamber to the top to get sun and heat from their hot siblings who were, until then, on top. In reality, it appears quite disorderly, as the wad’s members churn to distribute heat more evenly throughout.
In arid regions especially, water loss through the skin is reduced when snakes gather into wads. Ecdysis (the shedding of skin) is a water-intensive process that may not happen properly if humidity is too low. Piling together with siblings, therefore, may help maintain favorable moisture and thermal conditions.
Physical contact with siblings may also help ease anxiety about predators because more heads are better than one at detecting threats. Should one baby spook and head for cover, everyone in the wad gets the message that that danger may be lurking. Such information, transmitted by touch, may be especially important when eyesight is diminished in the days leading up to ecdysis.
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