सर्पव्यालत्रासनार्थं गोचरानुपातज्ञानार्थं च त्रस्नूनां घण्टातूर्यं च बध्नीयुः ॥ कZ_०२.२९.२२ ॥
sarpavyālatrāsanārthaṃ gocarānupātajñānārthaṃ ca trasnūnāṃ ghaṇṭātūryaṃ ca badhnīyuḥ
To frighten off snakes and wild beasts, and to know the movement along grazing routes, they shall fasten bells and sounding instruments on timid (animals).
They are both deterrents (noise repels predators) and monitoring devices (sound reveals herd location and abnormal movement).
Practical, inexpensive controls (upāya) embedded in routine operations to reduce risk without heavy manpower.