Table 2. Ethogram of the observed behaviours during tests.

Criteria	Description
Animal’s first visit side	Left: animal had its snout within a max distance of 0.5 m around the left bowl
	Right: animal had its snout within a max distance of 0.5 m around the right bowl
Latency to visit the first bowl	Latency (seconds) from the opening of the starting area door until animal made a first visit
Look at the experimenter	Absent: no look at all after entry
	Glance: look less than 1 s after entry
	Stare: look more than 1s after entry
Contact with the experimenter	Presence: Any form of direct contact with experimenter 2: sniffing, touching, biting, stepping…
	Absence: no contact with experimenter 2
Trajectory	Direct trajectory: straight walk to the bowl
	Indirect: non-straight walk to the bowl. Any contact with experimenter 2 before a visit was considered as an indirect trajectory.