Brihat Samhita
विनाउपघातेन पिपीलिकानाम् अण्डौपसंक्रान्तिरहिव्यवायः । द्रुमावरोहश् च भुजङ्गमानां वृष्टेर्निमित्तानि गवां प्लुतं च ॥ २८-०७ ॥
If the ant, when undisturbed and of its own accord, should leave its hole with its egg, if serpents should be found to copulate or to climb up trees, there will be immediate rain.
english translation
vinAupaghAtena pipIlikAnAm aNDaupasaMkrAntirahivyavAyaH । drumAvarohaz ca bhujaGgamAnAM vRSTernimittAni gavAM plutaM ca ॥ 28-07 ॥
hk transliteration by Sanscript