  Based on the recent proposal for the tetraquarks with the mixing scheme, we
investigate fall-apart decays of $a_0(980), a_0(1450)$ into two lowest-lying
mesons. This mixing scheme suggests that $a_0(980)$ and $a_0(1450)$ are the
tetraquarks with the mixtures of two spin configurations of diquark and
antidiquark. Due to the relative sign differences in the mixtures, the
couplings of fall-apart decays into two mesons are strongly enhanced for
$a_0(980)$ but suppressed for $a_0(1450)$. We report that this expectation is
supported by their experimental decays. In particular, the ratios of the
associated partial decay widths, which depend on some kinematical factors and
the couplings, are found to be around $\Gamma [a_0(980)\rightarrow \pi
\eta]/\Gamma [a_0(1450)\rightarrow \pi \eta] = 2.51-2.54$, $\Gamma
[a_0(980)\rightarrow K\bar{K}]/\Gamma [a_0(1450)\rightarrow K\bar{K}] =
0.52-0.89$, which seems to agree with the experimental ratios reasonably well.
This agreement can be interpreted as the tetraquark signatures for $a_0(980),
a_0(1450)$.
