To solve \( 3^{-4} \) using the property of negative integer exponents, we can use the rule that states:
\[ a^{-n} = \frac{1}{a^n} \]
Applying this to \( 3^{-4} \):
\[ 3^{-4} = \frac{1}{3^4} \]
Now, we need to calculate \( 3^4 \):
\[ 3^4 = 3 \times 3 \times 3 \times 3 = 81 \]
So, we have:
\[ 3^{-4} = \frac{1}{81} \]
Thus, the final answer is:
\[ \frac{1}{81} \]