feeler
noun [ C usually plural ] uk/ˈfiː.lər/ us/ˈfiː.lɚ/
（昆虫的）触角，触须
one of the two long parts on the head of an insect and some other creatures with which it touches things in order to discover what is around it
Idiom
put out feelersidiom （作决定前）试探
to make informal suggestions as a way of testing other people's opinions on something before any decisions are made