Castro Valley's Colony-Elimination Ant Team

Contact spray disrupts the trail temporarily but rarely reaches the nest.

They're larger than most household ants, often black or black-and-red, and you may notice small wood shavings near baseboards.

Colony elimination via bait typically takes one to two weeks as it spreads through the nest.

Yes — mounds often need direct treatment plus broadcast baiting, since a colony can have multiple mounds scattered widely.

Bait removes the existing colony, and ongoing perimeter service reduces the odds of a repeat. Seasonal exterior treatment is the most reliable way to prevent a fresh colony from moving in after the current one clears.

Bait sits in enclosed stations or protected areas specifically to limit pet and child access. It also helps to keep mulch pulled back from the foundation a few inches, since that alone reduces bridge points significantly.