The courtship and courtship displays in the Narrow-billed Tody are like the rest of the todies and other Coraciiformes, the use of aerial flights and tumbles without distinctive vocalizations (Kepler 1977). Wing rattling appears to be a “unique” trait to tody courtship and has been suggested to resemble some of the manakin (Pipridae) species (Sick 1967).
All tody species nest by using excavated burrows in embankments (typical nesting strategy for most Coraciiformes). The average nest dimensions for the Narrow-billed Tody is 4.4 cm wide by 3.9 cm high (n=57; Kepler 1977: 93, Table 1). The depth of the burrow is approximately 30 cm in the Narrow-billed Tody. The bank height for the where the burrows are excavated is approximately 3 m. Both male and females of the species (including all tody species) dig the burrow and usually begin as early as September, with excavation continuing through June. They vigorously defend the burrow from any trespassers (humans and mongooses included) (Kepler 1977).
Tody eggs are the smallest of all the Coraciiformes (considered roughly the size of wren eggs). The mean size of the egg is 15.5 x 13.5 mm (n=5) (Kepler 1977). The egg has a very white shell that is glossy and fragile (Kepler 1977). Clutch size for this species (and all tody species) is one to four eggs, usually laid between April and July. Incubation for this species is approximately 2-3 weeks, depending on the season, with both sexes developing brood patches and jointly incubating the eggs (the female has a larger proportion of the incubating times) (Kepler 1977). The nestling period is also approximately 2-3 weeks long, after that the young fledge and the nesting pair separates.