mouse

A mouse is a small binding, typically made from spun yarn, twine, or wire, that is wrapped tightly around the gap between a fish hook's shank and its point. Its purpose is to prevent the hook from opening, straightening, or unhooking under load, particularly when hauling heavy tackle or recovering snagged equipment. In shipyard and marine rigging work, a secure hook is critical: a failed hook during cargo operations or salvage work creates both economic loss and genuine danger.

The binding itself is simple. Spun yarn or small-diameter line is wound repeatedly around the base of the hook point where it meets the shank, then seized off tightly. Wire mousings, more permanent and common in professional marine settings, are wrapped in the same fashion and twisted to lock. The thickness varies with the hook size and the load it will carry: a small fish hook might use single-stranded yarn, while a large lifting hook in a shipyard gets multiple passes of galvanized wire or stainless steel.

The term mouse appears in rigging texts as early as the 18th century, though its origin is unclear. Some sources suggest it comes from the resemblance of the wrapped binding to a small mouse's body, or from the verb meaning to bind or wrap. Whatever the etymology, the name is established and universal in maritime trade. A hook without a mousing is said to be "unmousèd" and is considered unsafe for heavy work.

Mousings fail when the binding material degrades, corrodes, or loosens from repeated stress. Spun yarn mousings can rot if exposed to moisture; wire mousings can corrode even in stainless steel if contaminants build up. They also fail if wrapped too loosely or over too short a span. A properly applied mousing should distribute pressure evenly and cover the full gap where the point emerges from the shank.

In modern shipyards, the choice between yarn and wire mousings depends on the hook's application. Deck tackle and temporary rigging often use tarred yarn or synthetic line because they are quick to apply and replace. Permanent lifting hooks and salvage equipment receive wire mousings, usually applied during hook manufacture or major overhaul. Regular inspection of mousings is standard practice in any operation where hook failure could cause injury or loss of cargo.