border electric fence grass limit metal pole post wire barrier colors colours danger electricity sign. electric fence warning wires barbed wire high voltage secure security voltage warn chock chocking electrical grid high power sundtech black current dangerous installation net sign station volt yellow cable conductor copper distribution insulator pylon railings substation supply transformer transmission animals Asian-elephant boulder brisles bristly calf Calves captive electric-fence elephant elephant-hide elephant-side elephants elephas-maximus fenced-in hair hairy herbivore Indian-elephant large largest-terrestrial-mammal mammal mammals play playful pushing rock rocks skin sociable strength strong texture textures tree-trunks trunk wiry wrinkled wrinkles young youngsters zoo eletric fences pile spring stem stems wood