Narcissus deters voles and rodents.
A good hunch · suboptimal if ignored → advise
How it works
Lycorine and related alkaloids are toxic; avoidance behaviour reported.
The evidence
Evidence: confirmed against 3 sources in the research-based literature.
the 3 sources
Univ. of Illinois Extension, 'Bulbs', extension.illinois.edu/flowers/bulbs (read 2026-07-11): field mice 'most often attack tulips, crocus and gladioli and rarely eat daffodils, alliums or colchicums.'
Univ. of Illinois Extension, 'Knowing poisonous plants can save a life', extension.illinois.edu/blogs/know-how-know-more/2022-07-05-knowing-poisonous-plants-can-save-life (read 2026-07-11): 'Daffodil, hyacinth, and narcissus contain the toxin lycorine, which, if eaten, typically causes nausea.'
Clemson HGIC, 'Planting Deer Resistant Bulbs', hgic.clemson.edu/planting-deer-resistant-fall-bulbs (read 2026-07-11): daffodils 'are also poisonous, so deer are not tempted to eat them.'