Guinea pigs are prey animals with excellent hearing, and a night of fireworks teaches them that the air itself can bang without warning. Owners are often surprised that the pigs are still flinching at cupboard doors two or three days later, but that lingering jumpiness is normal settling, not a new problem to fix with fussing. What settles them is a short list of physical comforts during the noise, then a stubborn return to ordinary life afterward.
During the Fireworks Themselves
Keep them indoors or in a sound-buffered room while fireworks continue, choosing the room in the house furthest from the street, with curtains drawn against flashes. An indoor cage moved before dark avoids a last-minute carry through a noisy garden, which pairs the frightening sounds with being grabbed. Partly cover the cage with a blanket to muffle flashes and bangs while keeping airflow open: drape the blanket over the top and one or two sides, and leave a side uncovered so air moves freely and the cage never warms or stuffs up. Check the cover once during the evening rather than repeatedly lifting it, since each lift lets in a fresh burst of light and noise.
Add extra hay and hides so everyone can bury in, with at least one hide per pig and a deep loose pile of hay in the middle of the cage. A guinea pig buried in hay with only its nose out feels hidden in a way a pig in an open run never does, and eating hay is itself settling, giving frightened pigs something rhythmic and familiar to do. Keep the household as ordinary as you can around them: normal voices, normal lights elsewhere in the house, and no stream of visitors peering in to check on them. Background household sound at its usual level masks odd distant bangs better than a hushed house where every bang stands alone.
The Days Afterward Matter Most
Afterward, restore the normal routine and wait out jumpiness over days, because predictability is the actual medicine here. Feed at the usual times, clean on the usual day, offer floor time in the usual place, and let the pigs choose whether to come out of their hides or stay in. Offer favorite vegetables by hand at the cage door and let each pig take food at its own pace; a pig that stretches out to take a pepper strip and retreats with it is recovering on schedule. Resist chasing anyone for a reassurance cuddle, since being pursued and lifted confirms a frightened pig's belief that the world has become grabby and unsafe.
Watch appetite and droppings as your recovery gauge over those days. Pigs who are eating hay, producing normal droppings, and starting to call for food at the usual times are settling, even if they still startle at sudden sounds. A pig who is still hiding constantly and not eating after about a day needs your vet's advice, because guinea pigs should not go long without eating and fear can tip a borderline appetite into a real problem. Keep notes on who ate and who hid if you have several pigs, since the confident one at the food bowl can hide the fact that a quieter companion has barely eaten.
Keeping the Whole Household on the Same Plan
Tell everyone in the house the plan before the night itself: doors closed gently, no picking up the pigs for a few days unless care requires it, and the blanket-and-hay setup left exactly as arranged. Children especially need the reason, because the instinct to comfort a scared pig by holding it is strong and kindly meant, and it works against settling. If a neighbor or relative is sitting with the pigs while you are out, leave the routine written down with feeding times and the cover arrangement, not just a verbal summary. A written note shared ahead of time beats a phone call from a noisy house. Families can hold that plan in KinsLe using Family Sharing, so a sitter opening the shared profile sees the feeding schedule, blanket arrangement and the notes you left on handling them gently.