To apply the property of negative integer exponents, we can rewrite \( 3^{-4} \) as follows:
\[ 3^{-4} = \frac{1}{3^{4}} \]
Now, we can calculate \( 3^{4} \):
\[ 3^{4} = 3 \times 3 \times 3 \times 3 = 81 \]
So, we can substitute this back into our expression:
\[ 3^{-4} = \frac{1}{3^{4}} = \frac{1}{81} \]
Thus, the final answer is:
\[ 3^{-4} = \frac{1}{81} \]