Why animal lists work in K–5
Animal names are short, concrete, and already in a child's spoken vocabulary. That is why a farm or pets word search works as morning work when a unit-vocab list would stall. The student is hunting CAT and HORSE, not CHLOROPHYLL.
Keep the grid matched to the reader. A 20×20 safari list on a first-grade desk is a 30-minute slog. A 10×10 farm list is ten minutes and a finished paper.
If you need a science tie-in, jump to the science word search page for food chains and habitats. For a stack of mixed sheets see word search worksheets.