观察后腿。 检查脚部。 看体型。 留意皮肤。 看颜色。

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You can tell the difference between a frog and a toad by the length of its legs. If you can get close enough, get a good look at the back legs specifically.  A frog's hind legs are very long, as frogs hop more frequently than toads. A frog's hind legs will be bigger than its head and body. A toad's hind legs will be smaller, as toads tend to crawl. Their hind legs will be shorter than their heads and bodies. Frogs have webbed feet, as they spend most of their life in water. They will usually have webbed back feet, and some will have webbed front feet. You may also see sticky pads on a frog's feet. Toad feet are generally not webbed and do not have pads. Frogs tend to be slender and athletic in appearance. Toads, on the other hand, are shorter and stubbier.  A slender looking amphibian, with longer limbs, is probably a frog. A short, chubby amphibian, with smaller legs, is likely a toad. Frog skin is a lot smoother than toad skin. A toad's skin will be bumpy in appearance. While a frog will have smooth, rubbery skin, a toad may look like it's covered in warts. In general, frogs are lighter colored than toads. They tend to look greener. While toads may have a greenish skin, they tend to be darker overall than frogs.  Toads come in various shades that range from a dark green to an olive green. Frogs are on the more yellowish, brighter side of the green spectrum. Frogs may have a yellow-olive color. However, do not rely on color alone. Always consider other factors, as some frogs do have a brownish green appearance.