Glass frogs seem able to condense and expand their red blood cells to make themselves almost invisible.

玻璃蛙似乎能够凝结和扩大它们的红细胞，使自己几乎隐形。

Enter a little critter called the glass frog.

进入一种叫玻璃蛙的小生物。

Enter a little critter called the glass frog. It's not actually transparent; it's translucent.

进入一种名为透明蛙的小生物。这种生物实际上并不是透明的；而是半透明的。

But when northern glass frogs wake up and move in search of insects and mates, they take on a partly clear, reddish-brown color.

但当北方玻璃蛙醒来并四处寻找昆虫和配偶时，它们会呈现出不透明的红棕色。

" Transparency is super rare in nature, and in land animals, it's essentially unheard of outside of the glass frog, " White said.

“透明在自然界中是极其罕见的，而在陆地动物中，除了玻璃蛙之外，几乎闻所未闻。”

The research " beautifully explains" how " glass frogs conceal blood in the liver to maintain transparency, " said Juan Manuel Guayasamin of University San Francisco of Quito, Ecuador.

厄瓜多尔旧金山基多大学的胡安·曼努埃尔·瓜亚萨明说，这项研究 “很好地解释了玻璃蛙是如何将血液隐藏在肝脏中以保持透明的”。

So regardless of whether the leaf is dark or bright, if the glass frog is sitting on it, it will appear to change to more closely match its background.

因此，无论叶子是暗还是亮，如果透明蛙坐在上面，它似乎能进行变化，以更接近背景颜色。