An "adder" typically refers to a snake species, known as the **adder** (Vipera berus), which is found in Europe. In this context, the length of an adder varies depending on factors like age, sex, and environment, but generally:
- **Adult adders** range in length from about **50 to 80 cm (20 to 31 inches)**, though some individuals can grow a bit longer, up to **90 cm (35 inches)**.
- **Females** are usually larger than males, with some females reaching up to 75 cm (about 30 inches), while males are often closer to 50-60 cm (about 20-24 inches).
In some regions, adders can occasionally be found in smaller sizes, particularly in areas with cooler climates. The adder's length is enough to make it an effective ambush predator in its environment, where it relies on its camouflage and quick strikes to capture prey, such as small mammals, birds, and amphibians.
If you were asking about a different kind of "adder," such as a machine or device, let me know, and I can provide more information specific to that context!