He should erect outer ramparts round his forts, and fill his trenches with water, putting pointed stakes at their bottom and filling them with crocodiles and sharks.
प्रगण्डीः कारयेत् सम्यगाकाशजननीस्तदा। आपूरयेच्च परिखां स्थाणुनक्रझषाकुलाम्॥