蝙蝠是如何排泄的？

是倒掛著排泄 還是先正過來 拉完 然後倒回去

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謝邀。

這是一個經典的shower thought。我沒有養過蝙蝠，所以無法證實下面的說法：

Do bats poop while hanging upside-down?（帖子里的吐槽也很精彩）

Urination: Bats have been observed urinating while in two different postures:

Tilted-away urinating: The bat hangs pendant by two feet. The wings are held partially abducted with the digits extended. The palmar surface of each wing is approximately parallel with the frontal plane. The bat "bends back" at the hips so that the genital region is foremost. Once in this position, the bat urinates. This position appears to prevent urine from contacting the bat"s fur.

Rotary-shake urinating: The bat hangs pendant from two feet while the wings are in a folded position at the bat"s side or slightly abducted. The long axis of the body is directly beneath and continuous with the long axis of the legs. As the urine is released, the bat rapidly (too fast to be observed as individual movements) rotates laterally about its long axis through an arc of about 45 degrees to either side of its saggital plane. During this movement, the legs are stationary. The effect is to spray most urine out and away (at least 1.5 m) from the bat, but some urine may also partially cover the batís fur.

Defecation: M.spasma defecates while in the "tilted-away" posture.

後仰式：蝙蝠以雙腳倒掛，翅膀展開，身體向後仰以避開墜下的尿液。

（我腦補的圖解）

抖動式：蝙蝠以雙腳倒掛，翅膀併攏或微張，身體基本垂直。排尿時以肉眼無法跟上的速度反覆左右旋轉身體，這可以將尿液抖到1.5米開外，不過還是有一些會沾到自己身上。

（腦補圖解2。目測這種體位對鄰居不太友善。）

不過我個人覺得最理想的方法還是自由飛翔式。

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用前肢第一指的指端勾住物體，排泄時保持頭上肛下。
人類不要動不動就yy人家「旋轉，跳躍，我尿一臉」了嘛……
附個油管視頻截圖（原視頻），有興趣的可以繼續翻牆搜索，相關視頻很多。

排泄過程略重口就沒有截圖，姿勢基本如箭頭所指的那隻蝙蝠所示，後面那隻沒有在排泄的蝙蝠採用的是常見的倒立姿勢。
不確定是否所有的翼手目都採用這種姿勢排泄，坐等專家來科普。

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我們是直立行走，平卧休息，但卻是蹲著拉屎（有馬桶以前的自然狀態），就是為了避免拉身上，所以我猜測，蝙蝠拉屎應該也會採取類似的規避動作，它們倒掛，所以仰卧起坐拉屎是個不錯的選擇，1-2-3-噗，1-2-3-噗…

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倒掛著排泄的，所以掛在低處的蝙蝠會被撒得一身屎，好在蝙蝠屎是顆粒狀的固體，問題不大。

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掛著拉趴著拉都有，據觀察我家那隻…拉之前會有點預備動作…

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