Correct Answer - Option 1 : 10

^{9}
**Given:**

Total number of ants = 1000 million

**Concept Used:**

1 million = 1000000 = 10^{6}

**Calculation:**

As, total number of ants in hole = 1000 million

∴ 1000 million = 1000 × 10^{6}

= 10^{3} × 10^{6}

= 10^{9}

**∴ The total number of ants is 10**^{9}.