Canto 2 -
Ayodhyā-kāṇḍa
Chapter 28: Rāma Refuses to Accept Her Request
Text 2.28.8

क्रीडमानाश्च विस्रब्धा मत्ताः शून्ये महामृगाः।
दृष्ट्वा समभिवर्तन्ते सीते दुःखमतो वनम्॥

krīḍamānāś ca visrabdhā mattāḥ śūnye mahā-mṛgāḥ
dṛṣṭvā samabhivartante sīte duḥkham ato vanam

krīḍamānāḥ = sportive; ca = and; visrabdhāḥ = fearless; mattāḥ = proud; śūnye = in the lonely forest; mahā-mṛgāḥ = great creatures; dṛṣṭvā = as soon as they see us; samabhivartante = will assail us; sīte = Sītā; duḥkham = is misery; ato = therefore; vanam = a forest.

Fearless, sportive, proud and great creatures in the lonely forest will assail us as soon as they see us. Sītā, therefore a forest is misery.

Great creatures such as lions and tigers would attack because they wouldn’t have seen any human being in the forest.