Why does this Hadith says camel shed tears out of sadness?

> It was narrated that "Abdullah bin Ja"far said: One day the > Messenger of Allah (ﷺ) seated me behind him on his mount, then he told > me something in secret that I will never tell to anyone. When he > relieved himself, what the Messenger of Allah (ﷺ) liked best to > conceal himself with was a small hill or a cluster of date palms. One > day he entered one of the gardens of the Ansar where he found a camel > that came to him, **groaning with tears in its eyes.** - Bahz and > "Affan said: When it saw the Prophet (ﷺ) it groaned with tears in its > eyes. - The Messenger of Allah (ﷺ) stroked its back and behind its > ears and it calmed down. He said: "Who is the owner of this camel?" A > young man of the Ansar came and said: it belongs to me, O > Messenger of Allah. He said: “Do you not fear Allah with regard to > this animal that Allah has put in your possession? It is complaining > to me that you keep it hungry and overburden it with work.” > > > Sahih (Darussalam) [ Muslim (342)] . > > Musnad Ahmad 1745 Arabic/English book : Book 20, Hadith 1745 Also according to islamweb.net this Hadith is sahih We know that animals don't shed tears out of sadness. Then why does this Hadith say it was shedding tears out of sadness?