Modifiers matching insectivore:

• small,
• terrestrial,
• mammalian,
• smaller,
• flying,
• avian,
• native,
• migrant,
• nocturnal,

Simple categories matching migrant:

• fish,
• thrush,
• group,
• population,
• bird,
• visa,
• labourer,
• waterbird,
• language,
• worker,
• passerine,
• sandpiper,
• songbird,
• sparrow,
• finch,
• warbler,
• shorebird,
• organization,
• insectivore,