An ant trail across a countertop is the visible end of a colony that may hold tens of thousands of workers and several queens. A can of repellent spray kills the trail and, in several common species, causes the colony to bud into satellite nests scattered through the wall voids. Three weeks later there are four trails instead of one.

Identify, then treat

Odorous house ants, pavement ants, carpenter ants and Pharaoh ants all look broadly similar from a doorway and respond to completely different approaches. Carpenter ants mean we are also looking for the moisture-damaged timber they are nesting in. Pharaoh ants mean no repellents anywhere, under any circumstances.

German cockroaches

• They breed indoors year-round and do not come in from outside.
• One egg case holds thirty to forty nymphs.
• They need water more urgently than food, which is why the treatment starts with a leak survey.

What we do

Gel bait goes into hinge voids, under appliance panels and along cracks where the insects actually travel. An insect growth regulator goes down alongside it so the next generation does not reach breeding age. Monitors stay in place, and we read them at each visit rather than asking whether things seem better.

Keeping it clear

The single most effective thing a household can do is deny water: fix the dripping trap, dry the sink at night, and empty the pet bowl. Food is easier to control than most people expect; water is what keeps a population alive between treatments.