Mouse violations — NYC
Managing the rat problem and ignoring the mice is how you end up with 10 critical violation points on one inspection.
DOHMH violation code 04L covers evidence of mice. It's a critical violation carrying the same minimum point value as 04K, triggering the same re-inspection cycle, with an identical fine structure. Most operators don't find this out until an inspector does.
What the violation means
04L: mice or evidence of mice in a food service establishment.
Code 04L is cited whenever an inspector finds evidence of mice anywhere in the food service establishment: prep areas, storage, front of house, or anywhere food is handled or stored. Evidence includes droppings, gnaw marks, nesting material, or live or dead rodents.
At 5 critical points minimum, a single 04L citation combined with one other critical violation puts a restaurant above 9 points — triggering a B or C grade depending on total score. The 28-point threshold for a C grade and potential closure can be crossed with a handful of rodent and sanitation citations on a single visit.
NYC restaurant closures for rodent violations are publicly reported. A mouse-related closure carries the same reputational damage as a rat closure — the distinction between 04K and 04L doesn't register with customers or local media.
Code 04L
Mice or evidence of mice — including live mice, dead mice, droppings, gnaw marks, or nesting material anywhere in the food service establishment.
Critical violation
Minimum 5 points per citation. Critical violations are weighted more heavily in scoring and trigger mandatory re-inspection cycles when uncorrected.
Fine structure
Fines range from $300 to $2,000 per violation depending on prior citation history and whether the violation is corrected at the time of inspection. Repeat violations carry higher penalties.
Re-inspection cycle
A critical violation triggers a follow-up inspection within a defined window. If the violation is still present at re-inspection, the point total is locked in and the grade reflects the full score.
What inspectors look for
Mouse evidence is harder to clear than most operators expect.
Droppings
Small rod-shaped droppings, typically 3–6mm, found along walls, behind equipment, in storage areas, and inside cabinets. A single mouse produces 50–75 droppings per day. Inspectors check corners, shelf edges, and floor gaps.
Gnaw marks
Mice gnaw continuously to keep their teeth in check. Look for gnaw marks on food packaging, wood baseboards, cardboard, and wiring. Marks are typically at lower heights than rat gnaw damage.
Nesting material
Shredded paper, fabric, insulation, or soft material gathered in concealed areas — behind equipment, inside wall voids, in rarely moved storage. Nesting presence indicates established activity, not just transient rodents.
Grease/rub marks
Mice leave faint smear marks along regularly traveled paths — wall edges, pipe runs, and entry points. Less pronounced than rat grease marks but visible on close inspection.
Live or dead mice
Direct sighting of live or dead mice anywhere in the establishment. This is an automatic 04L citation regardless of other conditions.
Entry points
Gaps as small as 6mm (the diameter of a pencil) are sufficient entry for a mouse. Inspectors note unsealed pipe penetrations, gaps under doors, and cracks at wall junctions as contributing conditions.
When both are present
04K and 04L can be cited at the same inspection.
Rats and mice rarely share territory — rats dominate and displace mice when both are present in the same space. But in a commercial building with multiple floors, compartments, or adjacent units, rats and mice can occupy separate areas simultaneously.
A single inspection that cites both 04K and 04L produces a minimum of 10 critical points from rodent violations alone. Combined with routine sanitation citations, crossing the 28-point closure threshold becomes straightforward.
Most pest control programs address rats and mice as separate problems with separate treatments. The 90-day fertility management program addresses both simultaneously — Evolve Rat and Evolve Mouse deployed in the same two-phase structure.
Point math — combined rodent violations
Code 04K — rats or evidence of rats
5+ pts
Code 04L — mice or evidence of mice
5+ pts
Subtotal — rodent violations alone
10+ pts
Typical sanitation violations (2–3)
6–9 pts
Total — realistic inspection score
16–19+ pts
Grade B threshold
14–27 pts
Grade C / potential closure
28+ pts
How the program addresses it
Same two-phase structure. Separate fertility management for each species.
Phase 1 knockdown — both species
Your existing pest control vendor treats for both rats and mice in Phase 1. Standard treatment methods work for both. The fertility layer goes in after a documented clean baseline is established for both.
Evolve Mouse deployment
Evolve Mouse is a separate SenesTech product using the same gossypol-based mechanism as Evolve Rat. Stations are placed along mouse travel paths — typically at lower heights, along wall edges, and near food storage. Same monthly monitoring and replenishment schedule.
Separate track count monitoring
Mouse tracking plates and rat tracking plates are deployed and tracked separately. Each has its own trend line in the monitoring record. This produces documentation specific to each violation code — useful if you're managing an active 04K and an active 04L simultaneously.
90-day monitoring record
The final report covers both species: track presence and density data by species, station-by-station breakdown, and a documented trend line you can hand to a DOHMH inspector as evidence of active management of both 04K and 04L conditions.
Rats and mice. One program. One monitoring record.
Tell us whether you're managing an active 04K, an active 04L, or both. We'll outline the station plan for your property and what the 90-day monitoring record will document.