An electric bidet seat has, at minimum, three ways to start a wash cycle: a button on a side panel bolted to the seat, buttons on a wireless remote that lives on a nearby wall or counter, and — on some models — an automatic trigger tied to the seat-occupancy sensor. Any of the three can fire without an adult intending it.
The side panel is the most common culprit with young children. It sits at exactly toddler height, right where a curious hand naturally lands while climbing onto or off of a step stool, and the icons are big, colorful and button-like — everything a toddler is trained by other objects in the house to want to press. A remote left on the bathroom counter is just as reachable, and unlike the panel it can be carried off and experimented with anywhere in the house.
Pets introduce a different failure mode. A cat walking across a closed lid, or jumping up to drink from an open bowl, can apply enough concentrated pressure through a paw to register on some seats' sensors, or can nudge a poorly seated remote sitting on the tank lid. Dogs are less often the direct trigger — most are too large to be on the seat — but a tail sweeping a counter-mounted remote onto the floor, buttons-down, has been enough in isolated reports to trip a cycle.
The through-line is the same in both cases: none of these mechanisms know who or what is touching them. A button is a button whether a toddler or an adult presses it, and a pressure sensor registers pressure whether it comes from a seated adult or 10 pounds of cat. That's exactly why seat-occupancy sensors and dedicated child modes matter — and why neither is a complete fix alone.